JavaScript prototypes are used to access the properties and methods of objects. Inherited properties are originally defined in the prototype or parent object. The Date object is inherited from Date.prototype, Array object inherits from Array.prototype, etc. The prototypes may be used to add new properties and methods to the existing objects and object constructor.
Syntax:
Object.prototype
Example 1: This example adds a new property to the object.
Javascript
function Student(a, b) {Â Â Â Â this.name = a;Â Â Â Â this.id = b;}Â
Student.prototype.age = 12;Â
const s1 = new Student("Dinesh", 1234567);Â
console.log(s1.name +Â Â Â Â " is " + s1.age + " years old."); |
Output
Dinesh is 12 years old.
Example 2: This example adds a new method to the object.
Javascript
function Student(a, b) {Â Â Â Â this.name = a;Â Â Â Â this.id = b;}Â
Student.prototype.details = function () {Â Â Â Â return this.name + " " + this.id};Â
let s1 = new Student("Dinesh", 1234567);Â
console.log(s1.details()); |
Output
Dinesh 1234567
