"use strict";

var add = function (a, b) {
    return a+b;

var sum = add;

console.log(add(2, 3));  // 5
console.log(sum(3, 4));  // 7

console.log(sum);        // [Function]
// function add(a, b) {
//     return a+b;
// }

We can assign the name of a function to a variable. Now we have the same function with two names. We can call both using the function_name() notation. We can even print the source code of the function in either of the variables.