The difference between include < > and include ""

One 、 The directories searched are different
1、#include<>： The compiler looks for the header file directly from the system class library directory ：

#include<stdio.h>

For example VS2013 in , The compiler will be directly in <Visual studio 2013 The installation directory >\VC\include Found under directory stdio.h This file , This is the class library directory of the compiler ; stay Linux GCC In the compiled environment , It's usually /user/include and /usr/local/include.

  If the search under the class library directory fails , The compiler will terminate the search , Direct error ：No such file or directory.

for example , We customize a header file "test.h", Put it in the directory where the project engineering documents are located , And then use “#include <>” Load header file in the form of test.h, Errors will be reported directly during compilation ：No such file or directory.