Hello, I am studying the pointer and i come to this program ....

#include <stdio.h>

void swap(int *,int *);

int main()
{
    int a=10;
    int b=20;
    swap(&a,&b);
    printf("the value is %d and %d",a,b);
    return 0;
}

void swap(int *a,int*b)
{
    int t;
    t=*a;
    *a=*b;
    *b=t;
    printf("%d and%d\n",*a,*b);
}

can any one tell me why this main function return the value reversed . The thing i understood till now is that the function call in c does not affect the main function and it's values .

I also want to know how much the space a pointer variable occupied like integer have occupied the 2 bytes and the various application use and advantages of the pointer ....

plz.... anyone help