Swap using Macros 

This example shows swapping two numbers using macros.

File Name  :   source/C/basic/swap.c  Author  :   Sudhakar KV Email  :   kvenkatasudhakar@gmail.com

view sourceprint? 01 #include<stdio.h> 02 #include<string.h> 03   04 #define swap_macro(a,b) a=a+b;b=a-b;a=a-b; 05   06 int swap(int a, int b){    07     a=a+b;b=a-b;a=a-b; 08     printf("inside swap x:%d  y:%d\n",a,b); 09 } 10   11 int main() 12 { 13     int x=2,y=8; 14     swap_macro(x,y); 15     printf("x:%d  y:%d\n",x,y); 16   17     //changes to x,y wont effect them 18     //in main as these params are passed by value 19     swap(x,y); 20     printf("x:%d  y:%d\n",x,y); 21           22     getch(); 23     return 0; 24 }

x:8  y:2
inside swap x:2  y:8
x:8  y:2