the Swapping of two Values using Functions

#include<stdio.h>

#include<conio.h>

int swapval(int,int);

int swapref(int*,int*);

int a,b;

void main()

{

clrscr();

printf(“enter the two values\n”);

scanf(“%d%d”,&a,&b);

printf(“pass by value\n”);

printf(“before function call a=%d b=%d “,a,b);

swapval(a,b);

printf(“after function swapval a=%d b=%d “,a,b);

printf(“pass by reference\n”);

printf(“before function call a=%d b=%d “,a,b);

swapref(&a,&b);

printf(“after function swapref a=%d b=%d “,a,b);

getch();

}

swapval(int x,int y)

{

int t;

t=x;

x=y;

y=t;

printf(“\nwith swap val x=%d y=%d”,x,y);

}

swapref(int*x,int*y)

{

int *t;

*t=*x;

*x=*y;

*y=*t;

printf(“\nwith swapref x=%d y=%d “,*x,*y);

}

Output:

give two numbers 

5

6

pass by value

 before function call a=5 b=6

with swapval x=6 y=5

after function swapval a=5 b=6

pass by reference

before function call a=5 b=6

with swapref x=6 y=5l

after function swapref a=6 b=5