{ C++ }

C++ Call By Reference

original value is modified

Passing arguments to a function copies the address of an argument into the formal parameter.In call by reference, original value is changed or modified because we pass address(reference).So actual and formal arguments shares the same address space.

#include
void incre(int  *v)
{
    *v = *v+1;
}
int main()
{
     int n=10;
     incre(&n);
     cout<<"Value of number is:" << n;
     return 0;
}

Output :
Value of number is: 11

Example : Swapping numbers using Function Call by reference

#include
void swap(int *a, int *b)
{
 int temp;
 temp=*a;
 *a=*b;
 *b=temp;
}
void main() 
{  
 int a=400, b=200;   
 swap(&a,&b);
 cout<<"Value of a:" << a;
 cout<<"Value of b:" << b;  
}  

Output:
Value of a: 200
Value of b: 400