mirror of
https://github.com/Aexiar/c.git
synced 2024-10-22 12:05:45 +00:00
208 lines
103 KiB
JavaScript
208 lines
103 KiB
JavaScript
|
import{_ as s,c as i,o as a,a5 as n}from"./chunks/framework.D1oHBMsh.js";const l="/coa6/assets/1.CXNJqOOc.png",e="/coa6/assets/2.E0LS08Y5.png",t="/coa6/assets/3.XcPl7d9s.png",p="/coa6/assets/4.DL02VQMp.png",h="/coa6/assets/5.Dr67r_Ws.png",d="/coa6/assets/6.C5XiXNVN.png",k="/coa6/assets/7.DO8XxSV6.jpg",r="/coa6/assets/8.CUXrdefp.jpeg",c="/coa6/assets/9.uqLiL_yu.png",o="/coa6/assets/10.CkykpHY2.png",E="/coa6/assets/11.DV1YbrOP.png",u="/coa6/assets/12.AHNJT9TV.png",b="/coa6/assets/13.Bs-MOwx2.png",g="/coa6/assets/14.StzjmBz-.png",F="/coa6/assets/15.C0wVWaxD.png",y="/coa6/assets/16.LXJMAihe.png",m="/coa6/assets/17._UTCq3PD.png",C="/coa6/assets/18.BjQ5kBL-.png",B="/coa6/assets/19.COIOzcmT.png",v="/coa6/assets/20.Cu__mjav.png",A="/coa6/assets/21.BX_KzkHt.png",_="/coa6/assets/22.COt_QxSP.png",S=JSON.parse('{"title":"第一章：变量（⭐）","description":"","frontmatter":{},"headers":[],"relativePath":"notes/01_c-basic/02_xdx/index.md","filePath":"notes/01_c-basic/02_xdx/index.md","lastUpdated":1720685105000}'),D={name:"notes/01_c-basic/02_xdx/index.md"},q=n('<h1 id="第一章-变量-⭐" tabindex="-1">第一章：变量（⭐） <a class="header-anchor" href="#第一章-变量-⭐" aria-label="Permalink to "第一章：变量（⭐）""></a></h1><h2 id="_1-1-程序中变化的数据" tabindex="-1">1.1 程序中变化的数据 <a class="header-anchor" href="#_1-1-程序中变化的数据" aria-label="Permalink to "1.1 程序中变化的数据""></a></h2><ul><li>在生活中，我们使用最多的不是固定的数据，而是会变化的数据： <ul><li>① 购物车商品的<code>数量</code>、<code>价格</code>等。</li><li>② 一首歌<code>播放的时间</code>、<code>进度条</code>、<code>歌词的展示</code>等。</li><li>③ 微信聊天中<code>消息条数</code>、<code>时间</code>、<code>语音的长度</code>、<code>头像</code>、<code>名称</code>等。</li><li>④ 游戏中技能的<code>冷却时间</code>、<code>血量</code>、<code>蓝量</code>、<code>buff 时间</code>、<code>金币的数量</code>等。</li><li>……</li></ul></li></ul><ul><li>下图是一个<code>购物车</code>中<code>变化</code>的<code>数据</code>，即：</li></ul><p><img src="'+l+'" alt=""></p><ul><li>那么，在实际开发中，我们就会使用<code>变量</code>来<code>保存</code>和<code>操作</code>这些<code>变化</code>的<code>数据</code>。</li></ul><h2 id="_1-2-变量" tabindex="-1">1.2 变量 <a class="header-anchor" href="#_1-2-变量" aria-label="Permalink to "1.2 变量""></a></h2><ul><li>变量的定义：变量是程序中不可或缺的组成单位，最基本的存储单元。其实，变量就是一个存储数据的临时空间，可以向其中存储不同类型的数据，如：整数、小数、字符、字符串等，并且变量中的数据在程序运行的时候可以动态改变。</li></ul><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><ul><li><code>变量</code>：用来<code>存储数据</code>的<code>容器</code>。</li><li><code>数据</code>：可以是一个用来计算的<code>数字</code>，如：上文购物车中的<code>价格</code>等；也可以是一句话中的<code>关键词</code>或<code>其它任意格式的数据</code>。</li><li>变量的<code>特别</code>之处就在于<code>它存放的数据是可以改变</code>的。</li></ul></div><ul><li>我们可以将<code>变量</code>想象为一个<code>容器</code>，盒子中<code>装的</code>就是我们想要的<code>数据</code>，并且我们需要<code>给</code>盒子<code>取</code>一个<code>特别的名称</code>；通过这个<code>特别的名称</code>，我们可以<code>给</code>盒子<code>添加数据</code>或<code>移除数据</code>，这个<code>特别的名称</code>就是<code>变量名</code>。</li></ul><p><img src="'+e+`" alt=""></p><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><ul><li>① <code>变量</code>是内存中的一个<code>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 声明一个整型变量，取名为 a</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> a;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 给变量赋值</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> a </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 10</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"a = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, a);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><ul><li>示例：初始化（声明变量的同时给其赋值）</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 声明一个整型变量，取名为 b ，并直接赋值（初始化，实际开发中最为常用）</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> b </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 200</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 修改变量 b 的值，将变量 a 的值赋值给变量 b</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> b </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 300</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"b= </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, b);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><ul><li>示例：同时声明多个变量并赋值</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 同时声明多个整型的变量并赋值</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> c1 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 10</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, c2 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 20</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, c3 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 30</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"c1 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, c1);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"c2 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, c2);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"c3 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, c3);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><h2 id="_1-4-输出变量" tabindex="-1">1.4 输出变量 <a class="header-anchor" href="#_1-4-输出变量" aria-label="Permalink to "1.4 输出变量""></a></h2><ul><li>在计算机中，所谓的<code>输入</code>和<code>输出</code>都是以计算机（CPU 和内存）为主体而言的，即：</li></ul><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><p>输入：从输入设备(键盘、鼠标、扫描仪)向计算机输入数据。</p><p>输出：从计算机向外部输出设备(显示器、打印机)输出数据。</p></div><p><img src="`+t+`" alt=""></p><ul><li>在 C 语言中，提供了 <code>printf()</code> 函数用于输出信息，其函数声明是：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> (</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> char</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> *</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">__format</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, ...) {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> ...</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><ul><li><code>printf</code> 的标准含义是格式化输出文本，来源于 <code>print formatted（格式化打印）</code>的缩写，其语法规则，如下所示：</li></ul><p><img src="`+p+'" alt=""></p><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><ul><li>格式化字符串：是使用双引号括起来的字符串，里面包含了普通的字符串和格式占位符。</li><li>格式占位符（格式声明符）：由 <code>%</code> 和<code>格式字符</code>组成，作用是将输出的数据转换为指定的格式后输出，这里的 <code>%d</code> 表示整数。</li><li>输出列表：是程序要输出的一些数据，可以是常量、变量或表达式，需要和格式占位符一一对应。</li></ul></div><ul><li><p>在计算机中，二进制、八进制、十进制以及十六进制的英文名称和缩写，如下所示：</p><ul><li>二进制（binary），缩写是 bin。</li><li>八进制（octal），缩写是 oct。</li><li>十进制（decimal），缩写是 dec。</li><li>十六进制（Hexadecimal），缩写是 hex。</li></ul></li><li><p>其实，我们也可以在 Windows 系统中的计算器中来看到，即：</p></li></ul><p><img src="'+h+`" alt=""></p><div class="important custom-block github-alert"><p class="custom-block-title">IMPORTANT</p><p></p><p>在生活中的 decimal 是小数的意思；但是，在 C 语言中，decimal 的完整含义是 decimal integer ，即十进制整数。</p></div><ul><li>示例：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 声明变量并赋值</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 18</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 使用输出语句，将变量 num 的值输出，其中 %d 表示输出的是整数</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"我今年</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">岁</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><h2 id="_1-5-输入数据赋值给变量" tabindex="-1">1.5 输入数据赋值给变量 <a class="header-anchor" href="#_1-5-输入数据赋值给变量" aria-label="Permalink to "1.5 输入数据赋值给变量""></a></h2><ul><li>在 C 语言中，提供了 <code>scanf()</code> 函数用于从标准输入（通常是键盘）中读取数据并根据变量的地址赋值给变量（变量需要提前声明），其函数声明是：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> scanf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> char</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> *</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">__format</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, ...) {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> ...</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><ul><li>其语法规则，如下所示：</li></ul><p><img src="`+d+`" alt=""></p><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><p><code>&age</code>、<code>&num</code> 中的 <code>&</code>是寻址操作符，<code>&age</code> 表示变量 <code>age</code> 在内存中的地址。</p></div><div class="caution custom-block github-alert"><p class="custom-block-title">CAUTION</p><p></p><ul><li><p>① scanf() 函数中的 <code>%d</code>，如果是连着写，即：<code>%d%d</code>，那么在输入数据的时候，数据之间不可以使用逗号<code>,</code>分隔，只能使用空白字符（空格、tab 键或回车键），即：<code>2空格3tab</code>或<code>2tab3回车</code>等。</p></li><li><p>② 如果是 <code>%d,%d</code>，则输入的时候需要加上逗号<code>,</code>，即：<code>2,3</code>。</p></li><li><p>③ 如果是 <code>%d %d</code>，则输入的时候需要加上空格，即：<code>2空格3</code>。</p></li></ul></div><ul><li>示例：计算圆的面积，半径由用户指定</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> float</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"请输入一个半径："</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> scanf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%f</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">&</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">radius);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> double</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> area </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 3.1415926</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> *</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"半径是</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%f</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">的圆的面积是</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%.2lf</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, radius, area);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><ul><li>示例：输入一个整数值，求其绝对值</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"请输入一个整数："</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> scanf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">&</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">num);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> absNum;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> if</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> (num </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"><</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> absNum </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> -</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">num;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> } </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">else</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> absNum </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> }</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">的绝对值是：</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, absNum);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br></div></div><ul><li>示例：输入多个变量的值，求其乘积</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> a, b, c;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"请输入整数 a 、b 和 c 的值："</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> scanf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> %d</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> %d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">&</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">a, </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">&</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">b, </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">&</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">c);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> result </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> a </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> b </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> c;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> × </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> × </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, a, b, c, result);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><h2 id="_1-6-标识符" tabindex="-1">1.6 标识符 <a class="header-anchor" href="#_1-6-标识符" aria-label="Permalink to "1.6 标识符""></a></h2><h3 id="_1-6-1-概述" tabindex="-1">1.6.1 概述 <a class="header-anchor" href="#_1-6-1-概述" aria-label="Permalink to "1.6.1 概述""></a></h3><ul><li>在 C 语言中，变量、函数、数组名、结构体等要素命名的时候使用的字符序列，称为标识符。</li></ul><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><p>在上世纪 60 - 70 年代的时候，因为国家贫穷，人民生活不富裕等原因，家长虽然会给孩子取名为：<code>张建国</code>、<code>李华强</code>等；但是，也会取小名为<code>二狗子</code>、<code>狗剩</code>等，目的是希望孩子能健康成长（养活），像 <code>张建国</code>、<code>李华强</code>、<code>二狗子</code>、<code>狗剩</code>都是名字（标识符），伴随人的一生。</p></div><h3 id="_1-6-2-标识符的命名规范" tabindex="-1">1.6.2 标识符的命名规范 <a class="header-anchor" href="#_1-6-2-标识符的命名规范" aria-label="Permalink to "1.6.2 标识符的命名规范""></a></h3><ul><li><p>强制规范：</p><ul><li>① 只能由<code>小写</code>或<code>大写英文字母</code>，<code>0-9</code> 或 <code>_</code> 组成。</li><li>② 不能以<code>数字</code>开头。</li><li>③ 不可以是<code>关键字</code>。</li><li>④ 标识符具有<code>长度</code>限制，不同编译器和平台会有所不同，一般限制在 63 个字符内。</li><li>⑤ 严格<code>区分大小写字母</code>，如：Hello、hello 是不同的标识符。</li></ul></li><li><p>建议规范：</p><ul><li>① 为了提高阅读性，使用有意义的单词，见名知意，如：sum，name，max，year 等。</li><li>② 使用下划线连接多个单词组成的标识符，如：max_classes_per_student 等。</li><li>③ 多个单词组成的标识符，除了使用下划线连接，也可以使用小驼峰命名法，除第一个单词外，后续单词的首字母大写，如： studentId、student_name 等。</li><li>④ 不要出现仅靠大小写区分不同的标识符，如：name、Name 容易混淆。</li><li>⑤ 系统内部使用了一些下划线开头的标识符，如：C99 标准添加的类型 <code>_Bool</code>，为防止冲突，建议开发者尽量避免使用下划线开头的标识符。</li></ul></li><li><p>示例：合法（不一定建议）的标识符</p></li></ul><div class="language-txt vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">txt</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span>a、BOOK_sun、MAX_SIZE、Mouse、student23、Football、FOOTBALL、max、_add、num_1、sum_of_numbers</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><ul><li>示例：非法的标识符</li></ul><div class="language-txt vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">txt</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span>$zj、3sum、ab#cd<EFBFBD>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 'A'</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 12.3</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> "你好"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><ul><li>示例：字面量常量</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"整数常量 =》</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"字符常量 =》</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%c\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">'A'</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"浮点数常量 =》</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%f\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">12.3</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"字符串常量 =》</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%s\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"你好"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><h2 id="_2-3-使用-define-定义常量" tabindex="-1">2.3 使用 #define 定义常量 <a class="header-anchor" href="#_2-3-使用-define-定义常量" aria-label="Permalink to "2.3 使用 #define 定义常量""></a></h2><ul><li><code>#define</code> 来定义常量，也叫作宏定义，就是用一个标识符来表示一个常量值，如果在后面的代码中出现了该标识符，那么编译时就全部替换成指定的常量值，即用宏体替换所有宏名，简称<code>宏替换</code>。</li><li>格式是：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">#define 常量名 常量值</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><div class="caution custom-block github-alert"><p class="custom-block-title">CAUTION</p><p></p><ul><li>① 其实<code>宏定义</code>的常量的<code>执行时机</code>是在<code>预处理</code>阶段，将所有<code>宏常量</code>替换完毕，才会继续编译代码。</li><li>② 不要以 <code>;</code> 结尾，如果有 <code>;</code> ，分号也会成为常量值的一部分。</li><li>③ <code># define</code> 必须写在 <code>main</code> 函数的外面！！！</li><li>④ <code>常量名</code>习惯用<code>大写字母</code>表示，如果多个单词，使用 <code>_</code> 来分隔，以便和变量区分。</li></ul></div><ul><li>示例：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#define</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> PI</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 3.1415926</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> double</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 2.5</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> double</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> area </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> PI </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"半径为</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%lf</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">的圆的面积是</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%.2lf</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, radius, area);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><h2 id="_2-4-const-关键字" tabindex="-1">2.4 const 关键字 <a class="header-anchor" href="#_2-4-const-关键字" aria-label="Permalink to "2.4 const 关键字""></a></h2><ul><li>C99 标准新增，这种方式跟定义一个变量是类似的；只不过，需要在变量的数据类型前加上 <code>const</code> 关键字。</li><li>和使用 <code>#define定义宏常量</code>相比，const 定义的常量有详细的数据类型，而且会在编译阶段进行安全检查，在运行时才完成替换，所以会更加安全和方便。</li><li>格式是：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> 数据类型 常量名 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> 常量值;</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><ul><li>示例：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> PI </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 3.1415926</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> double</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 2.5</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> double</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> area </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> PI </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">*</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> radius;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"半径为</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%lf</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">的圆的面积是</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%.2lf</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, radius, area);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><h2 id="_2-5-枚举常量" tabindex="-1">2.5 枚举常量 <a class="header-anchor" href="#_2-5-枚举常量" aria-label="Permalink to "2.5 枚举常量""></a></h2><ul><li>格式：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">enum</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> 枚举常量 {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> xxx </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> yyy;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> ...</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br></div></div><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><ul><li>① 默认情况下，枚举常量是从 0 开始递增的。</li><li>② 也可以在定义枚举常量的时候，自定义它们的值。</li></ul></div><ul><li>示例：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">enum</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> sex {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> MALE </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">,</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> FEMALE </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 2</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">,</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">};</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, MALE);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, FEMALE);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><ul><li>示例：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">enum</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> Sex {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> MALE </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">,</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> FEMALE </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 2</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">,</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">};</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> enum</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> Sex sex;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"请输入性别(1 表示男性, 2 表示女性)："</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> scanf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">&</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">sex);</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"您的性别是：</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, sex);</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br></div></div><h2 id="_2-6-defind-定义常量-vs-const-定义常量" tabindex="-1">2.6 #defind 定义常量 VS const 定义常量 <a class="header-anchor" href="#_2-6-defind-定义常量-vs-const-定义常量" aria-label="Permalink to "2.6 #defind 定义常量 VS const 定义常量""></a></h2><ul><li>① 执行时机：<code>#define</code> 是预处理指令，在编译<code>之前</code>执行；<code>const</code> 是关键字，在编译<code>过程</code>中执行。</li><li>② 类型检查：<code>#define</code> 定义常量<code>不用指定类型</code>，<code>不进行类型检查</code>，只是简单地文本替换；<code>const</code> 定义常量<code>需要指定数据类型</code>，<code>会进行类型检查</code>，类型安全性更强。</li></ul><h1 id="第三章-二进制" tabindex="-1">第三章：二进制 <a class="header-anchor" href="#第三章-二进制" aria-label="Permalink to "第三章：二进制""></a></h1><h2 id="_3-1-概述" tabindex="-1">3.1 概述 <a class="header-anchor" href="#_3-1-概述" aria-label="Permalink to "3.1 概述""></a></h2><ul><li>计算机的底层只有<code>二进制</code>，即计算机中<code>运算</code>和<code>存储</code>的<code>所有数据</code>都需要转换为<code>二进制</code>，包括：数字、字符、图片、视频等。</li></ul><p><img src="`+k+'" alt=""></p><ul><li>之前，我们也提到现代的计算机（量子计算机除外）几乎都遵循<code>冯·诺依曼</code>体系结构，其理论要点如下： <ul><li>① <strong>存储程序</strong>：<code>程序指令</code>和<code>数据</code>都存储在计算机的内存中，这使得程序可以在运行时修改。</li><li>② <strong>二进制逻辑</strong>：所有数据和指令都以<code>二进制</code>形式表示。</li><li>③ <strong>顺序执行</strong>：指令按照它们在内存中的顺序执行，但可以有条件地改变执行顺序。</li><li>④ <strong>五大部件</strong>：计算机由<code>运算器</code>、<code>控制器</code>、<code>存储器</code>、<code>输入设备</code>和<code>输出设备</code>组成。</li><li>⑤ <strong>指令结构</strong>：指令由操作码和地址码组成，操作码指示要执行的操作，地址码指示操作数的位置。</li><li>⑥ <strong>中心化控制</strong>：计算机的控制单元（CPU）负责解释和执行指令，控制数据流。</li></ul></li><li>所以，再次论证了为什么计算机只能识别二进制。</li></ul><h2 id="_3-2-进制" tabindex="-1">3.2 进制 <a class="header-anchor" href="#_3-2-进制" aria-label="Permalink to "3.2 进制""></a></h2><h3 id="_3-2-1-常见的进制" tabindex="-1">3.2.1 常见的进制 <a class="header-anchor" href="#_3-2-1-常见的进制" aria-label="Permalink to "3.2.1 常见的进制""></a></h3><ul><li>在生活中，我们最为常用的进制就是<code>十进制</code>，其规则是<code>满 10 进 1</code> ，即：</li></ul><p><img src="'+r+`" alt=""></p><ul><li>在计算机中，常见的进制有<code>二进制</code>、<code>八进制</code>和<code>十六进制</code>，即： <ul><li>二进制：只能 0 和 1 ，满 2 进 1 。</li><li>八进制：0 ~ 7 ，满 8 进 1 。</li><li>十六进制：
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num1 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> 0b</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">10100110</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 二进制</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num2 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> 0</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">717563</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 八进制</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num3 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 1000</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 十进制</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num4 </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> 0x</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">af72</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 十六进制</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"num1 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num1);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // num1 = 166</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"num2 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num2);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // num2 = 237427</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"num3 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num3);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // num3 = 1000</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"num4 = </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num4);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // num4 = 44914</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br></div></div><h3 id="_3-2-3-输出格式" tabindex="-1">3.2.3 输出格式 <a class="header-anchor" href="#_3-2-3-输出格式" aria-label="Permalink to "3.2.3 输出格式""></a></h3><ul><li>在 C 语言中，可以使用不同的<code>格式占位符</code>来<code>输出</code>不同<code>进制</code>的整数，如下所示： <ul><li><code>%d</code>：十进制整数。</li><li><code>%o</code> ：八进制整数。</li><li><code>%x</code>：十六进制整数。</li><li><code>%#o</code> ：显示前缀 <code>0</code> 的八进制整数。</li><li><code>%#x</code> ：显示前缀 <code>0x</code> 的十六进制整数。</li><li><code>%#X</code> ：显示前缀 <code>0X</code> 的十六进制整数。</li></ul></li></ul><div class="caution custom-block github-alert"><p class="custom-block-title">CAUTION</p><p></p><p>C 语言中没有输出二进制数的格式占位符！！！</p></div><ul><li>示例：</li></ul><div class="language-c vp-adaptive-theme line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">c</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">#include</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> <stdio.h></span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">int</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> main</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> int</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> num </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 100</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 的十进制整数： </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, num);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 100 的十进制整数： 100</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 的八进制整数： </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%o\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, num);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 100 的八进制整数： 144</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 的十六进制整数： </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%x\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, num);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 100 的十六进制整数： 64</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 的八进制（前缀）整数： </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%#o\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, num);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 100 的八进制（前缀）整数： 0144</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 的十六进制（前缀）整数： </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%#x\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, num);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 100 的十六进制（前缀）整数： 0x64</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> printf</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%d</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> 的十六进制（前缀）整数： </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">%#X\\n</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">"</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, num, num);</span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;"> // 100 的十六进制（前缀）整数： 0X64</span></span>
|
|||
|
|
<span class="line"></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> return</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 0</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
|
|||
|
|
<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><h2 id="_3-3-进制的转换" tabindex="-1">3.3 进制的转换 <a class="header-anchor" href="#_3-3-进制的转换" aria-label="Permalink to "3.3 进制的转换""></a></h2><h3 id="_3-3-1-概述" tabindex="-1">3.3.1 概述 <a class="header-anchor" href="#_3-3-1-概述" aria-label="Permalink to "3.3.1 概述""></a></h3><ul><li>不同进制的转换，如下所示：</li></ul><p><img src="`+c+'" alt=""></p><ul><li>在计算机中，数据是从右往左的方式排列的；其中，最右边的是低位，最左边的是高位，即：</li></ul><p><img src="'+o+'" alt=""></p><h3 id="_3-3-2-二进制和十进制的转换" tabindex="-1">3.3.2 二进制和十进制的转换 <a class="header-anchor" href="#_3-3-2-二进制和十进制的转换" aria-label="Permalink to "3.3.2 二进制和十进制的转换""></a></h3><h4 id="_3-3-2-1-二进制转换为十进制" tabindex="-1">3.3.2.1 二进制转换为十进制 <a class="header-anchor" href="#_3-3-2-1-二进制转换为十进制" aria-label="Permalink to "3.3.2.1 二进制转换为十进制""></a></h4><ul><li>规则：从最低位开始，将每个位上的数提取出来，乘以 2 的 （位数 - 1 ）次方，然后求和。</li></ul><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><ul><li>① 在学术界，将这种计算规则，称为<code>位权相加法</code>。</li><li>② <code>八进制转换为十进制</code>、<code>十六进制转换为十进制</code>和<code>二进制转换为十进制</code>的算法相同！！！</li></ul></div><ul><li>示例：十进制转十进制</li></ul><p><img src="'+E+'" alt=""></p><ul><li>示例：二进制转十进制</li></ul><p><img src="'+u+'" alt=""></p><h4 id="_3-3-2-2-十进制转换二进制" tabindex="-1">3.3.2.2 十进制转换二进制 <a class="header-anchor" href="#_3-3-2-2-十进制转换二进制" aria-label="Permalink to "3.3.2.2 十进制转换二进制""></a></h4><ul><li>规则：将该数不断除以 2 ，直到商为 0 为止，然后将每步得到的余数倒过来，就是对应的二进制。</li></ul><div class="note custom-block github-alert"><p class="custom-block-title">NOTE</p><p></p><ul><li>① 在学术界，将这种计算规则，称为<code>短除法</code>或<code>连续除2取余法</code>。</li><li>② 很好理解，只有不断地除以 2 ，就能保证最大的数字不超过 2 ，这不就是二进制（只能有 0 或 1）吗？</li><li>③ <code>八进制转换为二进制</code>、<code>十六进制转换为二进制</code>和<code>十进制转换为二进制</code>的算法相同！！！</li></ul></div><ul><li>示例：十进制转十进制</li></ul><p><img src="'+b+'" alt=""></p><ul><li>示例：十进制转二进制</li></ul><p><img src="'+g+'" alt=""></p><h3 id="_3-3-3-二进制转八进制" tabindex="-1">3.3.3 二进制转八进制 <a class="header-anchor" href="#_3-3-3-二进制转八进制" aria-label="Permalink to "3.3.3 二进制转八进制""></a></h3><ul><li><p>规则：每 3 位二进制就是一个八进制。</p></li><li><p>示例：011 101 001 -> 351</p></li></ul><p><img src="'+F+'" alt=""></p><h3 id="_3-3-4-二进制转十六进制" tabindex="-1">3.3.4 二进制转十六进制 <a class="header-anchor" href="#_3-3-4-
|