关于C语言的问题:什么是宏? [英] Question about the C language: what is a macro?

问题描述

什么是宏?为什么在C语言中使用它?

删除了喊叫

What is a macro? Why it is used in C?

removed shouting

推荐答案

不要喊叫(不要只使用大写字母)！太粗鲁了！
阅读此内容: http://en.wikipedia.org/wiki/C_preprocessor [

Don''t shout (don''t use only capital letters)! It is rude!
Read this: http://en.wikipedia.org/wiki/C_preprocessor[^]

http://gcc.gnu.org/onlinedocs/cpp/Macros.html [ http://stackoverflow.com/questions/1358232/why-use-macros-in-c [ ^ ]

http://gcc.gnu.org/onlinedocs/cpp/Macros.html[^]
http://stackoverflow.com/questions/1358232/why-use-macros-in-c[^]

宏是C 编译器甚至看不到的东西.

根据 quick-Google-search (宏-C预处理器 [ ^ ]):

A macro is something the C compiler not even sees.

According to the first entry in a quick-Google-search (Macros - The C Preprocessor[^]):

宏是已被赋予名称的代码片段.每当使用该名称时，它就会被宏的内容替换.

A macro is a fragment of code which has been given a name. Whenever the name is used, it is replaced by the contents of the macro.

也就是说:

• 宏是C 预处理器的东西.
• 使用Google，您可能会找到很多有关的文档.



That is:

• macros are C preprocessor stuff.
• Using Google you may find a lot of documentation about.

#define BUFSIZE  100
//...
int buf[BUFSIZE];
//...
if (k>BUFSIZE)
{
  //...
}



预处理器用数字100替换每次出现的宏BUFSIZE，因此 C编译器解析(类似)以下源:





the preprocessor replaces every occurrence of the macro BUFSIZE with the number 100, thus the C compiler parses (something like) the following source:



//...
int buf[100];
//...
if (k>100)
{
  //...
}




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