if endif

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

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,

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

"# 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

#ifndef#define#endif的用法#ifndef#define#endif的用法  你所遇到的这几个宏是为了进行条件编译。一般情况下，源程序中所有的行都参加编译。但是有时希望对其中一部分内容只在满足一定条件才进行编译，也就是对一部分内容指定编译的条件，这就是“条件编译”。有时，希望当满足某条件时对一组语句进行编译，而当条件不满足时则编译另一组语句。     条件编译命令最常见的形式为：     #ifdef 标识符     程序段1     #else     程序段2

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 annotations such as "//" in C ++, but

Time: 2014.07.01 Location: Base ---------------------------------------------------------------------------- I. Pre-processing details before compiling conditions, first understand the pre-processing process. The pre-processing process reads the