what use of include in c

From: http://blog.csdn.net/suwei19870312/article/details/6665305 In some large projects, there may be dozens of basic classes, which are inevitably referenced by each other (not satisfying the inheritance relationship, but composite relationship ).

<> First, find the header file in the system directory. If the file is not found in the current directory. So use this method like standard header files stdio. h and stdlib. h. "" Is first searched in the current directory. If it cannot be found,

The role of file inclusion The so-called "file contains" processing means that a source file can include the entire contents of another source file, which will be included in the document. C + + provides the #include command to implement the "file

In C + + code, include is required when a file needs to use the classes, structs, constants, and so on that are defined in another file. When using include, you can have no rules, random include. But the result of this is not looping nesting, which

To put it simply:. h is the header file for standard C, and No. h is the standard C + + header file, both of which are header files. The reason for the difference between these two forms is that the development history of C + + is decided, just

The  include (), require () statement contains and runs the specified file. The two structures are exactly the same on the containing file, and the only difference is the handling of the error. The require () statement stops when it encounters a

C ++ File include rule constant definition To sum up, C ++'s function declaration, variable declaration, and class definition are written in the header file, while function implementation, variable definition, and class method implementation are

The usage of include and require in PHP is different from that in PHP. include () and require () have the same functions. include (include_once) and require (require_once) both read the included file code to the specified location, but there is a

In a powerful language such as C ++ programming language, there is a lot of profound content that deserves further research. For example, the C ++ include mechanism introduced today is one of the hard-to-understand aspects. Let's take a look at this.

Two cases are differentiated:1, #include <> compiler will only go to the System file directory to find, can not find the error.2, #include "" The compiler will look in the user directory first, then to the compiler set directory to find, and finally