RegExp.prototype.multiline

Baseline Widely available

This feature is well established and works across many devices and browser versions. It's been available across browsers since July 2015.

The multiline accessor property of RegExp instances returns whether or not the m flag is used with this regular expression.

Try it

const regex1 = /^football/;
const regex2 = /^football/m;

console.log(regex1.multiline);
// Expected output: false

console.log(regex2.multiline);
// Expected output: true

console.log(regex1.test("rugby\nfootball"));
// Expected output: false

console.log(regex2.test("rugby\nfootball"));
// Expected output: true

Description

RegExp.prototype.multiline has the value true if the m flag was used; otherwise, false. The m flag indicates that a multiline input string should be treated as multiple lines. For example, if m is used, ^ and $ change from matching at only the start or end of the entire string to the start or end of any line within the string.

Note: To match the start and end of the entire string in m mode, use the buffer boundary assertions \A, \z, and \Z.

The set accessor of multiline is undefined. You cannot change this property directly.

Examples

Using multiline

const regex = /^foo/m;

console.log(regex.multiline); // true

Specifications

Specification
ECMAScript® 2027 Language Specification # sec-get-regexp.prototype.multiline

Browser compatibility

	Desktop					Mobile							Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`multiline`	1	12	1	5	1	18	4	10.1	1	1.0	4.4	1	1.0.0	1.0	0.10.0
`prototype_accessor`	48	12	38	35	1.3	48	38	35	1	5.0	48	1	1.0.0	1.0	6.0.0