1 #include <stdio.h>
 2 
 3 void swap(int x,int y)
 4 {
 5     int temp;
 6     
 7     temp = x;
 8     x = y;
 9     y = temp;
10     printf("In swap: x = %d,y = %d\n",x,y);
11 }
12 
13 void swap_with_pt(int * x,int * y)
14 {
15     int temp;
16     
17     temp = *x;
18     *x = *y;
19     *y = temp;
20     printf("In swap_with_pt: x = %d,y = %d\n",*x,*y);
21 }
22 
23 int main()
24 {
25     int x = 5,y = 10;
26     
27     printf("Before swap: x = %d,y = %d\n",x,y);
28     swap(x,y);
29     printf("After swap: x = %d,y = %d\n",x,y);
30     printf("-------------------------------\n");
31     printf("Before swap_with_pt: x = %d,y = %d\n",x,y);
32     swap_with_pt(&x,&y);
33     printf("After swap_with_pt: x = %d,y = %d\n",x,y);
34     
35     return 0;
36 }

1 Before swap: x = 5,y = 10
2 In swap: x = 10,y = 5
3 After swap: x = 5,y = 10
4 ---------------------------------
5 Before swap_with_pt: x = 5,y = 10
6 In swap_with_pt: x =10,y = 5
7 After swap_with_pt: x = 10,y = 5