C语言预处理命令之条件编译,预处理过程扫描源代码，对其进行初步的转换，产生新的源代码提供给编译器.-C language preprocessor condition compilation, preprocessing scan source code, their initial conversion, to generate new source code available to the compiler.

预处理过程扫描源代码，对其进行初步的转换，产生新的源代码提供给编译器。可见预处理过程先于编译器对源代码进行处理(The preprocessing process scans the source code, performs a preliminary conversion, and generates new source code for the compiler. It is evident that the preprocessing process processes the sou