Javascript Programming

JavaScript Methods and this Keyword

In this tutorial, you will learn about JavaScript object methods and this keyword with the help of examples.

In JavaScript, objects can also contain functions. For example,

// object containing method
const person = {
    name: 'John',
    greet: function() { console.log('hello'); }

In the above example, a person object has two keys (name and greet), which have a string value and a function value, respectively.

Hence basically, the JavaScript method is an object property that has a function value.

Accessing Object Methods

You can access an object method using a dot notation. The syntax is:


You can access property by calling an objectName and a key. You can access a method by calling an objectName and a key for that method along with (). For example,

// accessing method and property
const person = {
    name: 'John',
    greet: function() { console.log('hello'); }

// accessing property; // John

// accessing method
person.greet(); // hello

Here, the greet method is accessed as person.greet() instead of person.greet.

If you try to access the method with only person.greet, it will give you a function definition.

person.greet; // ƒ () { console.log('hello'); }

JavaScript Built-In Methods

In JavaScript, there are many built-in methods. For example,

let number = '23.32';
let result = parseInt(number);

console.log(result); // 23

Here, the parseInt() method of Number object is used to convert numeric string value to an integer value.

To learn more about built-in methods, visit JavaScript Built-In Methods.

Adding a Method to a JavaScript Object


You can also add a method in an object. For example,

// creating an object
let student = { };

// adding a property = 'John';

// adding a method
student.greet = function() {

// accessing a method
student.greet(); // hello

In the above example, an empty student object is created. Then, the name property is added. Similarly, the greet method is also added. In this way, you can add a method as well as property to an object.

JavaScript this Keyword

To access a property of an object from within a method of the same object, you need to use the this keyword. Let’s consider an example.

const person = {
    name: 'John',
    age: 30,

    // accessing name property by using
    greet: function() { console.log('The name is' + ' ' +; }



The name is John

In the above example, a person object is created. It contains properties (name and age) and a method greet.

In the method greet, while accessing a property of an object, this keyword is used.

In order to access the properties of an object, this keyword is used following by . and key.

Note: In JavaScript, this keyword when used with the object’s method refers to the object. this is bound to an object.

However, the function inside of an object can access it’s variable in a similar way as a normal function would. For example,

const person = {
    name: 'John',
    age: 30,
    greet: function() {
        let surname = 'Doe';
        console.log('The name is' + ' ' + + ' ' + surname); }



The name is John Doe
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