CALL BY REFERENCE:

CALL BY REFERENCE:

The Changes made in the formal arguments will reflect to actual parameters(arguments).

/* Example for call by reference  */

#include<stdio.h>
#include<conio.h>
void swap(int*,int*);
 main()
{
int i,j;
printf("enter the values of i and j :");
scanf("%d %d",&i,&j);
swap(&i,&j);
printf("values of i and j after function call: i=%d  j=%d",i,j);
return 0;
getch();
}
void swap(int* p,int *q)
{
*p=*p+*q;
*q=*p-*q;
*p=*p-*q;
printf("values of p and q in function : p=%d  q=%d",p,q);
}

 Swapping program in c using function using Temporary variable

 #include<stdio.h>

 void swap(int *,int *);
int main(){
     int a,b;
     printf("Enter any two integers: ");
    scanf("%d%d",&a,&b);
     printf("Before swapping: a = %d, b=%d",a,b);
    swap(&a,&b);
     printf("\nAfter swapping: a = %d, b=%d",a,b);
    return 0;

}

void swap(int *a,int *b){                                         // a=a^b;
  int *temp;                                                               // b=a^b;
    temp = a;                                                              // a=a^b;
   *a=*b;                                                                  //or   a=(a*b)/(b=a); or a=a+b – (b=a);   a=a*b;         
    *b=*temp;                                                          // a^=b^=a^=b;                                                                  
}                                                                                ////a=a*b;b=a/b; a=a/b;or            

Sample output:

Enter any two integers: 3 6
Before swapping: a = 3, b=6
After swapping: a = 6, b=6