Swapping using reference variable

Write a program to swap the content of two variables using a reference variable.

#include<iostream>
using namespace std;
void swap_data(int&,int&);
int main()
{
	int a = 2, b = 4;
	cout << "a = " << a << " b = " << b << endl;
	swap_data(a,b);
	cout << "a = " << a << " b = " << b << endl;
	return 0;
}
void swap_data(int &i,int &j)
{
	int t;
	t = i;
	i = j;
	j = t;
}

Output

a = 2 b = 4
a = 4 b = 2