Call by Value and Call by reference Program

GTU Data Structure Practical - 1

Introduction to pointers. Call by Value and Call by reference.

Call by Value

				
					#include<stdio.h>
 void swap(int,int);
 int main()
{
         int a,b;
         printf("\nEnter a Value of A=");
         scanf("%d",&a);
         printf("\nEnter a Value of B=");
         scanf("%d",&b);
         swap(a,b);
         printf("\nOld Values:");
         printf("A=%d  B=%d \n",a,b);
}
void swap(int p,int q)
{
        int tmp;
        tmp=p;
        p=q;
        q=tmp;
        printf("New Values After Swap:");
        printf("A=%d B=%d",p,q);
}

Output

Call by Reference

				
					#include<stdio.h>
 void swap(int*,int*);
 int main()
{
         int a,b;
         printf("\nEnter a Value of A=");
         scanf("%d",&a);
         printf("\nEnter a Value of B=");
         scanf("%d",&b);
         swap(&a,&b);
         printf("\nOld Values:");
         printf("A=%d  B=%d \n",a,b);
}
void swap(int *p , int *q)
{
        int tmp;
        tmp=*p;
        *p=*q;
        *q=tmp;
        printf("New Values After Swap:");
        printf("A=%d B=%d",*p,*q);
}

Output