Edit Link error highlights under VC

1. 'std ': does not exist or is not a namespace

Error: Using namespace STD; an error is returned.

Cause: Unknown

Modify: used with <iostream>

Note: <iostream. h> cannot be used. It is different from <iostream>, and the two files are also different. <Iostream. h> is the usage of C. The input/output stream is defined as a global namespace. <iostream> is a standard C ++ usage. It is not a global namespace when called. It uses namespace STD; the namespace STD encapsulates the name of the standard library. to distinguish the standard library from the previous header files, it is generally not added ". h"

# Include <iostream> using namespace STD;