c - C中#define和#pragma有什么区别

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到目前为止，我知道 #define 是标准的，而 #pragma 不是标准的，但它们之间还有什么其他区别。

Answer 1

尝试 Microsoft 的链接 for Pragma和 for Define

定义:

The #define directive causes the compiler to substitute token-string for each occurrence of identifier in the source file. The identifier is replaced only when it forms a token.

编译指示:

The pragma directive is used to access compiler-specific preprocessorextensions. A common use of #pragma is the #pragma once directive,which asks the compiler to include a header file only a single time,no matter how many times it has been imported