c语言function prototypes

A function prototype in C language is a declaration of the function that specifies the function name, return type, and parameter types. It is used to inform the compiler about the function before it is called, so that the compiler can check the correctness of the function call and generate appropriate code.

The syntax of function prototype is:

return_type function_name(parameter_type parameter_name);

For example, the following function prototype declares a function that takes two integer parameters and returns an integer value:

int add(int x, int y);

Here, "int" is the return type, "add" is the function name, and "(int x, int y)" specifies the two integer parameters.

Function prototypes are typically placed in header files, which are included in source files that use the functions. This allows the compiler to check the correctness of the function calls and generate appropriate code. It also makes the code more modular and easier to maintain.