Why can't I properly do subtraction in this code [closed] - c

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#include<stdio.h>
int subtractNumbers(int n1,int n2);
int main(){
int n1,n2,difference;
printf("Enter Two Numbers: ");
scanf("%i%i",&n1,&n2);
subtractNumbers(n1,n2);
printf("The Difference is %i", n1,n2);
}
int subtractNumbers(int n1,int n2)
{
int result;
result =n1-n2;
return result;
}
Why can't this code properly do a subtraction?

Answer 1

Have to store the return value in 'difference' variable. (As I guess the 'difference' variable is meant for that)
In case of 'printf("The Difference is %i", n1,n2);' I guess the intention is to print the 'difference'. So change to 'printf("The Difference is %i", difference);'
#include<stdio.h>
int subtractNumbers(int n1,int n2);
int main(){
int n1,n2,difference;
printf("Enter Two Numbers: ");
scanf("%i%i",&n1,&n2);
difference = subtractNumbers(n1,n2); // stored the returend result
printf("The Difference is %i", difference); //printing only the result
}
int subtractNumbers(int n1,int n2)
{
int result;
result =n1-n2;
return result;
}

Answer 2

So basically you've mixed up the syntax. It's all right, but when you call your function, it's ok that you return a value, but the in your main you don't read that value.
This fixes it:
#include<stdio.h>
int subtractNumbers(int n1,int n2);
int main(){
int n1,n2,difference;
printf("Enter the first number : ");
scanf("%d",&n1);
printf("Enter the second number: ");
scanf("%d", &n2);
int result = subtractNumbers(n1,n2);
printf("The Difference is %d", result);
}
int subtractNumbers(int n1,int n2)
{
int result;
result = n1-n2;
return result;
}

Answer 3

Primary problem corrected like other answers, but with more commentary and a few "upgrades"...
#include <stdio.h>
// Please spread things out for your readers. Whitespace is free!
// if function PRECEEDS its use, it is its own "function prototype"
int subtractNumbers( int n1, int n2 )
{
int result = n1 - n2; // declare and assign together
return result;
}
int main() {
printf( "Enter Two Numbers: " );
// define variables "close" to when they are first used
int n1, n2;
// ALWAYS check return codes from system functions. Things go wrong
if( scanf( "%i%i", &n1, &n2 ) != 2 )
printf( "Something went wrong\n" );
else
{
// here was where the returned value was not being received. fixed.
int difference = subtractNumbers( n1, n2 );
printf( "The Difference is %i", difference );
}
return 0; // optional with some compilers
}