Header file --- # include <***. h> and # include "***. H"

The header file contained in the "<>" method is used to allow the compiler to search for the corresponding header file in the preset standard path of the compiler. If no header file is found, an error is returned.

For example, the installation directory \ Microsoft Visual Studio 9.0 \ Vc \ include of vs contains the header file of the standard library.

The second method means to search in the path where the project is located. If the project fails, search in the standard path of the system.

Therefore, it is worth special attention that, if it is a standard library header file, you can use both the <> method and the "" method,WhileUser-Defined header files can only be "".

For example, the following method is correct:

# Include <iostream>High Efficiency

# Include "iostream"Low Efficiency

The following method is incorrect:

# Include <mytest. h> // mytest. H is the header file we created.