How to use .call() and .apply()

CallApply.js

/* CallApply.js
 * How to use .call() and .apply()
 * Author : Sabbir Ahmed
 * Mail : <mail[at]thesabbir.com>
 * Date : 6-May-2015
 */


// Lets create a User Object
var User = function(name, age){
    // Properties
    this.name = name;
    this.age = age;

    // Methods
    this.find = function() {
    // Returns a JSON Object
    return {
        "name" : this.name,
        "age" : this.age
       };
    }
}

// Lets define a function that changes name property
// Note: this equals GLOBAL
var changeName = function(name, note) {
    console.log(note);
    this.name = name;
};

// Lets create an admin user
var admin = new User('sabbir', 20);

// Here is how we call method of an object
// Call find method. this equals to admin object.
// lets log the result
console.log("Untouched: ");
console.log(admin.find());

// Remove name. Using a function.
// Note: we are suppliying the value of this.
changeName.call(admin, 'Firoz', 'After Typo Fixed: ');
// Log
console.log(admin.find());

//Same thing using .apply()
changeName.apply(admin, ['Supreme Leader Aladin', 'After no more democracy: ']);
console.log(admin.find());