Pass by reference means addresses are sent as arguments.
The call by reference or pass by reference method passes the arguments to a function by the means of address to an argument. This is done into the formal parameter. Inside the function, the address is used to access an actual argument.
Example
#include<stdio.h>
void main(){
void swap(int *,int *);
int a,b;
printf("enter 2 numbers");
scanf("%d%d",&a,&b);
printf("Before swapping a=%d b=%d",a,b);
swap(&a, &b); //address are sent as an argument
printf("after swapping a=%d, b=%d",a,b);
getch();
}
void swap(int *a,int *b){
int t;
t=*a;
*a=*b; // *a = (*a + *b) – (*b = * a);
*b=t;
}Output
When the above program is executed, it produces the following result −
enter 2 numbers 10 20 Before swapping a=10 b=20 After swapping a=20 b=10