c if endif

Some programs are debugging, compatibility, in situations like platform porting, you might want to generate a different software by simply setting some parameters, which, of course, can be done with variable settings, write all the possible code,

Reprint: http://blog.chinaunix.net/uid-26854432-id-3181585.html #if语句 #if语句会计算它后面的表达式, and checks the result of the expression, if the result is true (true), the subsequent statement is compiled, and if False (false), the subsequent statement is

What is the effect of this sentence? The condition is always false, used to skip some code snippets, to skip the code between #if 0 and #endif at compile time, which causes #if 0---#endif之间的语句不会被编译, which is a precompiled statement. When commenting

  The pre-processing process scans the source code and performs initial conversion to generate new source code for the compiler. It can be seen that the preprocessing process processes the source code prior to the compiler. In C language, there is

Some programs in debugging, compatibility, platform porting and so on may want to create a different software by simply setting some parameters, this can of course, through the variable settings, all the code can be used to write in the

The preprocessing process scans the source code, makes a preliminary conversion, and generates a new source for the compiler. The preprocessing process can be seen before the source code is processed by the compiler.In the C language, there is no

there are always "#ifdef __cplusplus when you look at some programs.extern "C" {#endif"The definition, figuring out what's going on:Microsoft-specific predefined macros__cplusplus Defined forC++programs only. That means, if it's C.++program, you

When you look at some programs, there's always"#ifdef __cplusplusextern "C" {#endif "definition, figuring out what's going on:Microsoft-specific predefined Macros__cplusplus Defined for C + + programs only.This means that if you are a C + + program,

When reading some programs, there are always"# Ifdef _ cplusplusExtern "C "{# Endif "to figure out what is going on: Microsoft-specific predefined macros_ Cplusplus defined for C ++ programs only.It means that if it is a C ++ programExtern "C "{And

"# If 0/# if 1... # endif" function, 1. Let's talk about the role of "# if 0/# if 1... # endif" first. You have mentioned a little bit above, but you have not mentioned any key points. We know that the C standard does not provide single-line style