function calsum should have a prototype??

[royroy]

#include<stdio.h>
void main()
{
int a,b,c,sum;
printf("\nEnter three num ");
scanf("%d%d%d",&a,&b,&c);
sum=calsum(a,b,c);
printf("\nsum=%d",sum);
}
calsum(x,y,z)
int x,y,z;
{
int d;
d=x+y+z;
return(d);
}

error on compiling on tc++

[Matticus]

You can define a function before "main()".

You can also define a function after "main()", but it must be declared before "main()" with a prototype.

// Method 1 - define a function before main

#include <stdio.h>

int sum(int a, int b)
{
    return a + b;
}

int main(void)
{
    int result;

    result = sum(2,3);

    return 0;
}

// Method 2 - define a function after main

#include <stdio.h>

int sum(int a, int b);  // function declaration, or prototype (note semicolon)

int main(void)
{
    int result;

    result = sum(2,3);

    return 0;
}

int sum(int a, int b)  // function definition (note no semicolon)
{
    return a + b;
}

The return type, function name, and function arguments in the function definition should match those of the function prototype.

[royroy]

thank you