Correct form to declare and use function in C.

 /*

   correct form to declare and use function in c 

   first declare before main() to avoid any error 

   then we can use it

   orr you declare funtions write code in them above main()

   it'll be easy and will be short 

   orr just delete the code part from calsum above main()

   and remove comment from calsum below main()

   you'll get another form of code 

*/

#include <stdio.h>

int calsum(int x, int y, int z)

{

   int d ;

d = x + y + z ;

return ( d ) ; 

}

 

void main()

{

int a, b, c, sum ;

printf ( "\nEnter any three numbers " ) ;

scanf ( "%d %d %d", &a, &b, &c ) ;

sum = calsum ( a, b, c ) ;

printf ( "\nSum = %d", sum ) ;

}

/*int calsum ( int x, int y, int z )

{

int d ;

d = x + y + z ;

return ( d ) ;

}*/