printf()中的c函数调用错误

Question

#include<stdio.h>
#include<conio.h>
int adder(int,int);
void main()
{
    int a,b;
    printf("enter nos");
    scanf("%d%d",&a,&b);
    adder( a,b);
    printf("sum is %d",adder);
    getch();
}
int adder(int x,int y)
{
    return x+y;
}

this program is not working.I think the code is right.Can you point out the error?

Answer 1

adder is a function, what you should printf is its return value.

And as @JonathanLeffler said, it's better to add a newline at the end if you want to ensure the output appears timely. So,

change

adder( a,b);
printf("sum is %d",adder);

to:

int result = adder(a,b);
printf("sum is %d\n", result);

or to:

printf("sum is %d\n", adder(a, b));