W3cubDocs

/JavaScript

empty

An empty statement is used to provide no statement, although the JavaScript syntax would expect one.

Syntax

;

Description

The empty statement is a semicolon (;) indicating that no statement will be executed, even if JavaScript syntax requires one.

The opposite behavior, where you want multiple statements, but JavaScript only allows a single one, is possible using a block statement, which combines several statements into a single one.

Examples

Empty loop body

The empty statement is sometimes used with loop statements. See the following example with an empty loop body:

let arr = [1, 2, 3];

// Assign all array values to 0
for (let i = 0; i < arr.length; arr[i++] = 0) /* empty statement */ ;

console.log(arr);
// [0, 0, 0]

Unintentional usage

It is a good idea to comment intentional use of the empty statement, as it is not really obvious to distinguish from a normal semicolon.

In the following example, the usage is probably not intentional:

if (condition);       // Caution, this "if" does nothing!
   killTheUniverse()  // So this always gets executed!!!

Specifications

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
Empty
3
12
1
3
3
5
1
18
4
10.1
4.2
1.0
1.0
0.10.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/Empty