What is function argument?

    Function arguments are given inside the parenthesis, preceded by their types and separated by commas. If a function does not use any argument, the word void is used inside the parenthesis. For example:

int getchar(void);

double pow(double x,double y);

The first function int getchar(void); return an integer value and does not take any arguments.

The second function double pow(double x,double y); takes two double arguments and return a value of the type double.