Pointers to Functions in c

when the pointers are passed as an argument,the memory location of the variable is stored instead of direct value. This leads to change in value in both function values and main values ,because of there address are shared instead of the values

#include
void swap(int *n1, int *n2);
int main()
{
int num1 = 5, num2 = 10;
// address of num1 and num2 is passed to the swap function
swap( &num1, &num2);
printf("Number1 = %d\n", num1);
printf("Number2 = %d", num2);
return 0;
}
void swap(int * n1, int * n2)
{
// pointer n1 and n2 points to the address of num1 and num2 respectively
int temp;
temp = *n1;
*n1 = *n2;
*n2 = temp;
}