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< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 项目名称和版本号< / span > < / span >
< span class = "line" > < span > project(c-study VERSION 1.0 LANGUAGES C)< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 设置 C 标准< / span > < / span >
< span class = "line" > < span > set(CMAKE_C_STANDARD 23)< / span > < / span >
< span class = "line" > < span > set(CMAKE_C_STANDARD_REQUIRED True)< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 辅助函数，用于递归查找所有源文件< / span > < / span >
< span class = "line" > < span > function(collect_sources result dir)< / span > < / span >
< span class = "line" > < span > file(GLOB_RECURSE new_sources " ${dir}/*.c" )< / span > < / span >
< span class = "line" > < span > set(${result} ${${result}} ${new_sources} PARENT_SCOPE)< / span > < / span >
< span class = "line" > < span > endfunction()< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 查找顶层 include 目录（如果存在）< / span > < / span >
< span class = "line" > < span > if (EXISTS " ${CMAKE_SOURCE_DIR}/include" )< / span > < / span >
< span class = "line" > < span > include_directories(${CMAKE_SOURCE_DIR}/include)< / span > < / span >
< span class = "line" > < span > endif ()< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 查找所有源文件< / span > < / span >
< span class = "line" > < span > set(SOURCES)< / span > < / span >
< span class = "line" > < span > collect_sources(SOURCES ${CMAKE_SOURCE_DIR})< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 用于存储已经处理过的可执行文件名，防止重复< / span > < / span >
< span class = "line" > < span > set(EXECUTABLE_NAMES)< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 创建可执行文件< / span > < / span >
< span class = "line" > < span > foreach (SOURCE ${SOURCES})< / span > < / span >
< span class = "line" > < span > # 获取文件的相对路径< / span > < / span >
< span class = "line" > < span > file(RELATIVE_PATH REL_PATH ${CMAKE_SOURCE_DIR} ${SOURCE})< / span > < / span >
< span class = "line" > < span > # 将路径中的斜杠替换为下划线，生成唯一的可执行文件名< / span > < / span >
< span class = "line" > < span > string(REPLACE " /" " _" EXECUTABLE_NAME ${REL_PATH})< / span > < / span >
< span class = "line" > < span > string(REPLACE " \\" " _" EXECUTABLE_NAME ${EXECUTABLE_NAME})< / span > < / span >
< span class = "line" > < span > string(REPLACE " ." " _" EXECUTABLE_NAME ${EXECUTABLE_NAME})< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 处理与 CMakeLists.txt 文件同名的问题< / span > < / span >
< span class = "line" > < span > if (${EXECUTABLE_NAME} STREQUAL " CMakeLists_txt" )< / span > < / span >
< span class = "line" > < span > set(EXECUTABLE_NAME " ${EXECUTABLE_NAME}_exec" )< / span > < / span >
< span class = "line" > < span > endif ()< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 检查是否已经创建过同名的可执行文件< / span > < / span >
< span class = "line" > < span > if (NOT EXECUTABLE_NAME IN_LIST EXECUTABLE_NAMES)< / span > < / span >
< span class = "line" > < span > list(APPEND EXECUTABLE_NAMES ${EXECUTABLE_NAME})< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 创建可执行文件< / span > < / span >
< span class = "line" > < span > add_executable(${EXECUTABLE_NAME} ${SOURCE})< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 查找源文件所在的目录，并添加为包含目录（头文件可能在同一目录下）< / span > < / span >
< span class = "line" > < span > get_filename_component(DIR ${SOURCE} DIRECTORY)< / span > < / span >
< span class = "line" > < span > target_include_directories(${EXECUTABLE_NAME} PRIVATE ${DIR})< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 检查并添加子目录中的 include 目录（如果存在）< / span > < / span >
< span class = "line" > < span > if (EXISTS " ${DIR}/include" )< / span > < / span >
< span class = "line" > < span > target_include_directories(${EXECUTABLE_NAME} PRIVATE ${DIR}/include)< / span > < / span >
< span class = "line" > < span > endif ()< / span > < / span >
< span class = "line" > < span > < / span > < / span >
< span class = "line" > < span > # 检查并添加 module 目录中的所有 C 文件（如果存在）< / span > < / span >
< span class = "line" > < span > if (EXISTS " ${DIR}/module" )< / span > < / span >
< span class = "line" > < span > file(GLOB_RECURSE MODULE_SOURCES " ${DIR}/module/*.c" )< / span > < / span >
< span class = "line" > < span > target_sources(${EXECUTABLE_NAME} PRIVATE ${MODULE_SOURCES})< / span > < / span >
< span class = "line" > < span > endif ()< / span > < / span >
< span class = "line" > < span > endif ()< / span > < / span >
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< span class = "line" > < span > endforeach ()< / 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 > < span class = "line-number" > 22< / span > < br > < span class = "line-number" > 23< / span > < br > < span class = "line-number" > 24< / span > < br > < span class = "line-number" > 25< / span > < br > < span class = "line-number" > 26< / span > < br > < span class = "line-number" > 27< / span > < br > < span class = "line-number" > 28< / span > < br > < span class = "line-number" > 29< / span > < br > < span class = "line-number" > 30< / span > < br > < span class = "line-number" > 31< / span > < br > < span class = "line-number" > 32< / span > < br > < span class = "line-number" > 33< / span > < br > < span class = "line-number" > 34< / span > < br > < span class = "line-number" > 35< / span > < br > < span class = "line-number" > 36< / span > < br > < span class = "line-number" > 37< / span > < br > < span class = "line-number" > 38< / span > < br > < span class = "line-number" > 39< / span > < br > < span class = "line-number" > 40< / span > < br > < span class = "line-number" > 41< / span > < br > < span class = "line-number" > 42< / span > < br > < span class = "line-number" > 43< / span > < br > < span class = "line-number" > 44< / span > < br > < span class = "line-number" > 45< / span > < br > < span class = "line-number" > 46< / span > < br > < span class = "line-number" > 47< / span > < br > < span class = "line-number" > 48< / span > < br > < span class = "line-number" > 49< / span > < br > < span class = "line-number" > 50< / span > < br > < span class = "line-number" > 51< / span > < br > < span class = "line-number" > 52< / span > < br > < span class = "line-number" > 53< / span > < br > < span class = "line-number" > 54< / span > < br > < span class = "line-number" > 55< / span > < br > < span class = "line-number" > 56< / span > < br > < span class = "line-number" > 57< / span > < br > < span class = "line-number" > 58< / span > < br > < span class = "line-number" > 59< / span > < br > < span class = "line-number" > 60< / span > < br > < span class = "line-number" > 61< / span > < br > < span class = "line-number" > 62< / span > < br > < span class = "line-number" > 63< / span > < br > < span class = "line-number" > 64< / span > < br > < / div > < / div > < ul > < li > 在 CLion 中正常运行代码：< / li > < / ul > < p > < img src = "/c/assets/9.DdSfz-Pf.gif" alt = "" > < / p > < ul > < li > 在 CLion 中通过 valgrind 运行代码：< / li > < / ul > < p > < img src = "/c/assets/10.BMocjVt7.gif" alt = "" > < / p > < h1 id = "第四章-指针的理解和定义-⭐" tabindex = "-1" > 第四章：指针的理解和定义（⭐） < a class = "header-anchor" href = "#第四章-指针的理解和定义-⭐" aria-label = "Permalink to "第四章：指针的理解和定义（⭐）"" > < / a > < / h1 > < h2 id = "_4-1-概述" tabindex = "-1" > 4.1 概述 < a class = "header-anchor" href = "#_4-1-概述" aria-label = "Permalink to "4.1 概述"" > < / a > < / h2 > < ul > < li > < / li > < / ul > < h2 id = "_4-2-普通变量和指针变量的区别" tabindex = "-1" > 4.2 普通变量和指针变量的区别 < a class = "header-anchor" href = "#_4-2-普通变量和指针变量的区别" aria-label = "Permalink to "4.2 普通变量和指针变量的区别"" > < / a > < / h2 > < p > 在 CLion 中使用 GDB 调试时，可以通过反编译代码来查看指针变量和普通变量的区别。下面是具体的步骤：< / p > < h3 id = "设置-gdb-调试器" tabindex = "-1" > 设置 GDB 调试器 < a class = "header-anchor" href = "#设置-gdb-调试器" aria-label = "Permalink to "设置 GDB 调试器"" > < / a > < / h3 > < ol > < li > 打开 CLion， < / li > < li > 确保你使用的是带有 GDB 支持的工具链（如 GCC 工具链）。< / li > < li > 在 CLion 的设置中，确保调试器设置为 GDB。< / li > < / ol > < h3
< 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;" > int< / span > < 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 style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > int< / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > *< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > p < / 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;" > a;< / span > < / span >
< span class = "line" > < span style = "--shiki-light:#6F42C1;--shiki-dark:#B392F0;" > std< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ::cout < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > < < < / span > < span style = "--shiki-light:#032F62;--shiki-dark:#9ECBFF;" > " a: " < / 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:#032F62;--shiki-dark:#9ECBFF;" > " , p: " < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > < < < / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > p < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > < < < / span > < span style = "--shiki-light:#6F42C1;--shiki-dark:#B392F0;" > std< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ::endl;< / span > < / 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 > < / div > < / div > < p > 在 CLion 中设置断点并开始调试，程序将在 < code > std::cout< / code > 行暂停。此时在调试控制台中输入以下命令：< / p > < ul > < li > < code > print a< / code > ：输出变量 < code > a< / code > 的值，应该是 < code > 10< / code > 。< / li > < li > < code > print p< / code > ：输出指针变量 < code > p< / code > 的值，即 < code > a< / code > 的地址。< / li > < li > < code > print *p< / code > ：输出指针 < code > p< / code > 指向的值，即 < code > 10< / code > 。< / li > < / ul > < p > 通过这些命令，你可以看到指针变量 < code > p< / code > 实际上存储的是一个地址，而普通变量 < code > a< / code > 存储的是一个整数值。< / p > < h4 id = "使用反汇编" tabindex = "-1" > 使用反汇编 < a class = "header-anchor" href = "#使用反汇编" aria-label = "Permalink to "使用反汇编"" > < / a > < / h4 > < p > 在某些情况下，你可能需要查看反汇编代码来更深入地理解变量的存储方式。使用以下命令可以查看当前函数的反汇编代码：< / p > < ul > < li > < code > disassemble< / code > ：反汇编当前函数的代码。< / li > < li > < code > x/4wx & a< / code > ：查看变量 < code > a< / code > 的内存内容。< / li > < / ul > < h3 id = "总结" tabindex = "-1" > 总结 < a class = "header-anchor" href = "#总结" aria-label = "Permalink to "总结"" > < / a > < / h3 > < p > 在 CLion 中使用 GDB 调试时，通过查看变量值和反汇编代码，可以清楚地区分指针变量和普通变量。指针变量存储地址，而普通变量存储实际的值，通过适当的 GDB 命令可以轻松辨别两者的区别。< / p > < h1 id = "第五章-指针的运算-⭐" tabindex = "-1" > 第五章：指针的运算（⭐） < a class = "header-anchor" href = "#第五章-指针的运算-⭐" aria-label = "Permalink to "第五章：指针的运算（⭐）"" > < / a > < / h1 > < h2 id = "_5-1-概述" tabindex = "-1" > 5.1 概述 < a class = "header-anchor" href = "#_5-1-概述" aria-label = "Permalink to "5.1 概述"" > < / a > < / h2 > < h2 id = "_5-2-总结" tabindex = "-1" > 5.2 总结 < a class = "header-anchor" href = "#_5-2-总结" aria-label = "Permalink to "5.2 总结"" > < / a > < / h2 > < ul > < li > < p > 在 C 语言中，< code > 普通变量< / code > 是直接存储< code > 数据< / code > 的< code > 变量< / code > 。对于普通变量，支持的操作包括：< / p > < ul > < li > ① < strong > 赋值操作< / strong > ：给变量赋值，如：< code > int a = 5< / code > 。< / li > < li > ② < strong > 算术运算< / strong > ：可以对数值类型的普通变量进行加、减、乘、除等运算，如：< code > a + b< / code > 、< code > a - b< / code > 、< code > a * b< / code > 、< code > a / b< / code > < / li > < li > ③ < strong > 关系运算< / strong > ：可以进行比较运算（大于、小于、等于等），如： < code > a > b< / code > 、< code > a == b< / code > 。< / li > < li > ④ < strong > 逻辑运算< / strong > ：对布尔类型的值进行与、或、非运算，如： < code > a & & b< / code > 、< code > a || b< / code > 、< code > !a< / code > 。< / li > < li > ⑤ < strong > 位运算< / strong > ：对整数类型的值进行位操作（与、或、异或、取反、左移、右移等），如： < code > a & b< / code > 、< code > a | b< / code > 、< code > a ^ b< / code > 、< code > ~a< / code > 、< code > a < < 2< / code > 、< code > a > > 2< / code > 。< / li > < li > ⑥ < strong > 自增自减运算< / strong > ： < code > a++< / code > 、< code > --a< / code > 等。< / li > < / ul > < / li > < li > < p > 在 C 语言中，< code > 指针变量< / code > 存储的是< code > 另一个变量< / code > 的< code > 地址< / code > 。对于指针变量，支持的操作包括：< / p > < ul > < li > ① < strong > 赋值操作< / strong > ：可以将一个地址赋值给指针，如： < code > int *p = & a;< / code > 。< / li > < li > ② < strong > 解引用操作< / strong > ： <EFBFBD>
2024-07-31 03:20:24 +02:00
< span class = "line" > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > int< / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > *< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ptr < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > =< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > arr;< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 这句话是合法的， < / 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;" > %p\n< / span > < span style = "--shiki-light:#032F62;--shiki-dark:#9ECBFF;" > " < / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > , arr);< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 打印数组名，会打印数组首地址< / 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;" > %p\n< / 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:#E36209;--shiki-dark:#FFAB70;" > arr< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > [< / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > 0< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ]);< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 打印第一个元素的地址< / 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 > < / div > < / div > < / li > < li > < p > < strong > 数组名是常量指针< / strong > ： < / p > < 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:#E36209;--shiki-dark:#FFAB70;" > arr< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > [< / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > 5< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ];< / span > < / span >
< span class = "line" > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > int< / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > *< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ptr < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > =< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > arr;< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 合法， < / span > < / span >
< span class = "line" > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ptr< / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > ++< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ;< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 合法， < / span > < / span >
< span class = "line" > < / span >
< span class = "line" > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // arr++; // 非法，编译错误，因为数组名是常量，不能改变< / 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 > < / li > < li > < p > < strong > sizeof运算符的结果不同< / strong > ： < code > sizeof< / code > 运算符对数组名和指针变量会得到不同的结果，数组名会返回整个数组的大小，而指针变量会返回指针本身的大小。< / p > < 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:#E36209;--shiki-dark:#FFAB70;" > arr< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > [< / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > 5< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ];< / span > < / span >
< span class = "line" > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > int< / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > *< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ptr < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > =< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > arr;< / 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;" > " sizeof(arr) = < / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > %lu\n< / 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;" > sizeof< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > (arr));< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 返回数组的大小， < / 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;" > " sizeof(ptr) = < / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > %lu\n< / 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;" > sizeof< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > (ptr));< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 返回指针的大小， < / 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 > < / li > < li > < p > < strong > 地址运算符的结果不同< / strong > ： < code > & < / code > 对数组名和指针变量会得到不同的结果，对数组名使用< code > & < / code > 会返回数组的地址，而对指针变量使用< code > & < / code > 会返回指针变量本身的地址。< / p > < 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:#E36209;--shiki-dark:#FFAB70;" > arr< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > [< / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > 5< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ];< / span > < / span >
< span class = "line" > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > int< / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > *< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > ptr < / span > < span style = "--shiki-light:#D73A49;--shiki-dark:#F97583;" > =< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > arr;< / 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;" > " Address of array: < / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > %p\n< / 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:#E36209;--shiki-dark:#FFAB70;" > arr< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > );< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 返回整个数组的地址< / span > < / span >
2024-08-01 04:02:42 +02:00
< 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;" > " Address of pointer: < / span > < span style = "--shiki-light:#005CC5;--shiki-dark:#79B8FF;" > %p\n< / 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:#E36209;--shiki-dark:#FFAB70;" > ptr< / span > < span style = "--shiki-light:#24292E;--shiki-dark:#E1E4E8;" > );< / span > < span style = "--shiki-light:#6A737D;--shiki-dark:#6A737D;" > // 返回指针变量ptr的地址< / 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 > < / li > < / ol > < p > 综上所述，通过这些示例和解释，可以看出数组名虽然在某些场合下可以像指针一样使用，但它并不是一个真正的指针变量，而是一个常量，表示数组的首地址。< / p > < / div > < / div > < / main > < footer class = "VPDocFooter" data-v-39a288b8 data-v-e257564d > <!-- [ --> <!-- ] --> < div class = "edit-info" data-v-e257564d > <!-- --> < div class = "last-updated" data-v-e257564d > < p class = "VPLastUpdated" data-v-e257564d data-v-e98dd255 > 上次更新: < time datetime = "2024-08-01T02:00:11.000Z" data-v-e98dd255 > < / time > < / p > < / div > < / div > < nav class = "prev-next" aria-labelledby = "doc-footer-aria-label" data-v-e257564d > < span class = "visually-hidden" id = "doc-footer-aria-label" data-v-e257564d > Pager< / span > < div class = "pager" data-v-e257564d > < a class = "VPLink link pager-link prev" href = "/c/notes/01_c-basic/05_xdx/" data-v-e257564d > <!-- [ --> < span class = "desc" data-v-e257564d > 上一篇< / span > < span class = "title" data-v-e257564d > 数组< / span > <!-- ] --> < / a > < / div > < div class = "pager" data-v-e257564d > < a class = "VPLink link pager-link next" href = "/c/notes/01_c-basic/07_xdx/" data-v-e257564d > <!-- [ --> < span class = "desc" data-v-e257564d > 下一篇< / span > < span class = "title" data-v-e257564d > 函数< / span > <!-- ] --> < / a > < / div > < / nav > < / footer > <!-- [ --> <!-- ] --> < / div > < / div > < / div > <!-- [ --> <!-- ] --> < / div > < / div > < footer class = "VPFooter has-sidebar" data-v-5d98c3a5 data-v-e315a0ad > < div class = "container" data-v-e315a0ad > < p class = "message" data-v-e315a0ad > Released under the MIT License.< / p > < p class = "copyright" data-v-e315a0ad > Copyright © 2024 许大仙< / p > < / div > < / footer > <!-- [ --> <!-- ] --> < / div > < / div >
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