Relationship between 5.7c and C ++

Interview Example 1: In the C ++ program, why should I add the extern "C" to call the function compiled by the C compiler "?

A: function Overloading is supported in C ++ and function Overloading is not supported in C. The name of the function in the library after being compiled by C ++ is different from that in C language. Assume that the prototype of a function is void Foo (int x, int Y ). after the function is compiled by the C compiler, its name in the library is _ Foo, while the C ++ compiler generates names such as _ foo_int_int.

C ++ provides the C-link exchange and formulation symbol extern "C" to solve the name matching problem.

Interview Example 2:How can I determine whether a program is compiled by C or C ++?

C ++ defines _ cplusplus during compilation.

C defines _ stdc during compilation.