JavaScript: Literals

This JavaScript tutorial explains how to use literals (string, number, boolean and null) in JavaScript with examples.

Description

We'll cover four types of literals - string literals, number literals, boolean literals and null literals.

String Literals

String literals are always surrounded by single quotes (') or double quotes (").

For example:

'ABC'
'TechOnTheNet'

"ABC"
"TechOnTheNet"

In JavaScript, you can declare a variable named h and give it the string value of 'TechOnTheNet'.

var h = 'TechOnTheNet';

or

var h = "TechOnTheNet";

Number Literals

Number literals can be written with or without decimal places. Number literals can be either positive numbers or negative numbers. If you do not specify a sign, then a positive number is assumed. Here are some examples of valid number literals:

15
3.14
-23

In JavaScript, you can declare a variable named counter and give it the numeric value of 15.

var counter = 15;

Boolean Literals

Boolean literals can either be true or false. These values are special keywords in JavaScript and don't need quotes. Here are the two types of Boolean literals:

true
false

In JavaScript, you can declare a variable named found and give it the Boolean value of false.

var found = false;

Null Literals

Null literals are a special literal value in JavaScript. A null represents the absence of a value. Here is a null literal:

null

In JavaScript, you can declare a variable named h and give it a value of null.

var h = null;