JavaScript Methods
THE WORLD'S LARGEST WEB DEVELOPER SITE
HTML CSS JAVASCRIPT SQL PHP BOOTSTRAP HOW TO JQUERY W3.CSS ANGULAR XML MORE FORUM EXAMPLES REFERENCES
×

JS Tutorial

JS HOME JS Introduction JS Where To JS Output JS Statements JS Syntax JS Comments JS Variables JS Operators JS Arithmetic JS Assignment JS Data Types JS Functions JS Objects JS Scope JS Events JS Strings JS String Methods JS Numbers JS Number Methods JS Arrays JS Array Methods JS Array Sort JS Dates JS Date Formats JS Date Get Methods JS Date Set Methods JS Math JS Random JS Booleans JS Comparisons JS Conditions JS Switch JS Loop For JS Loop While JS Break JS Type Conversion JS Bitwise JS RegExp JS Errors JS Debugging JS Hoisting JS Strict Mode JS Style Guide JS Best Practices JS Mistakes JS Performance JS Reserved Words JS Versions JS JSON

JS Forms

JS Forms Forms API

JS Objects

Object Definitions Object Properties Object Methods Object Constructors Object Prototypes

JS Functions

Function Definitions Function Parameters Function Invocation Function Call Function Apply Function Closures

JS HTML DOM

DOM Intro DOM Methods DOM Document DOM Elements DOM HTML DOM CSS DOM Animations DOM Events DOM Event Listener DOM Navigation DOM Nodes DOM Collections DOM Node Lists

JS Browser BOM

JS Window JS Screen JS Location JS History JS Navigator JS Popup Alert JS Timing JS Cookies

JS AJAX

AJAX Intro AJAX XMLHttp AJAX Request AJAX Response AJAX XML File AJAX PHP AJAX ASP AJAX Database AJAX Applications AJAX Examples

JS JSON

JSON Intro JSON Syntax JSON vs XML JSON Data Types JSON Objects JSON Arrays JSON Parse JSON Stringify JSON PHP JSON HTML JSON JSONP

JS Examples

JS Examples JS HTML DOM JS HTML Input JS HTML Objects JS HTML Events JS Browser JS Quiz JS Certificate

JS References

JavaScript Objects HTML DOM Objects


JavaScript Object Methods

❮ Previous Next ❯

JavaScript Methods

JavaScript methods are the actions that can be performed on objects.

A JavaScript method is a property containing a function definition.

Property Value
firstName John
lastName Doe
age 50
eyeColor blue
fullName function() {return this.firstName + " " + this.lastName;}

Methods are functions stored as object properties.

The this Keyword

In JavaScript, the thing called this, is the object that "owns" the JavaScript code.

The value of this, when used in a function, is the object that "owns" the function.

Note that this is not a variable. It is a keyword. You cannot change the value of this.

Accessing Object Methods

You access an object method with the following syntax:

objectName.methodName()

You will typically describe fullName() as a method of the person object, and fullName as a property.

The fullName property will execute (as a function) when it is invoked with ().

This example accesses the fullName() method of a person object:

Example

name = person.fullName();
Try it Yourself »

If you access the fullName property, without (), it will return the function definition:

Example

name = person.fullName;
Try it Yourself »

Using Built-In Methods

This example uses the toUpperCase() method of the String object, to convert a text to uppercase:

var message = "Hello world!";
var x = message.toUpperCase();

The value of x, after execution of the code above will be:

HELLO WORLD!

Adding a Method to an Object

Adding a new method to an object is easy:

Example

person.name = function () {
    return this.firstName + " " + this.lastName;
};
Try it Yourself »

❮ Previous Next ❯