after some research, due to not really clear example in chapter 1.7 in "the C Programming language" by K & R, I understood that return is conventionally present at the end of each function, marking its end; it seems that by default, the value of return is 0, which means that the function was performed successfully (which exactly means what?). what happens if we set the value of return to the variable we call? for example, if I will write:

return p;

does it mean that the final value of the funcion will be p? So for example, if I call this funcion from main(), or another function, will the value of this function, inside main() be p?

Example:

#include <stdio.h>

int power(int m, int n);
/* test power function */
int main(){
    
    int i;
    for(i = 0; i < 10;   i)
        printf("%d - =", i, power(2,i), power(-3,i));
    return 0;
    }


int power(int base, int n)
{
    int i, p;
    p=1;

    for(i=1;i<=n;  i)
        p=p*base;

    return p;
}

does it mean that when i call power() in main its value is p?

CodePudding user response：

The value returned by power is the value of p.

Functions don't have a value; functions return a value.

p is not a value; p is a variable.

The value returned by power is the value of p when return p is evaluated. So if the value of p is 8, the value returned is 8.

The above program passes the returned value to printf to print.

it seems that by default, the value of return is 0

Functions don't have a default return value. If the function has a return type other than void, return must be used.

main is the sole exception. return 0 is the default for main.