As others have pointed out, you can only have one return statement from a function and thus only return on parameter (although it can be a structure).
In this instance I would pass the integer values into the function by using integer pointers and passing their address e.g.:
int swapNum(int *num1, int *num2);
int main()
{
int a = 2;
int b = 3;
printf("a=%d b=%d\n",a,b);
swapNum(&a, &b);
printf("a=%d b=%d\n",a,b);
return 0;
}
int swapNum(int *num1, int *num2)
{
int tempNumber;
tempNumber = *num1;
*num1 = *num2;
*num2 = tempNumber;
return 0;
}
Output
a=2 b=3
a=3 b=2
3
solved Swap number bug