RegExp.$1, …, RegExp.$9 - JavaScript | MDN

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deprecated RegExp features

Note: All RegExp static properties that expose the last match state globally are deprecated. See deprecated RegExp features for more information.

String.prototype.replace()

Because $1–$9 are static properties of RegExp, you always use them as RegExp.$1, RegExp.$2, etc., rather than as properties of a RegExp object you created.

RegExp.prototype.test()

The following script uses the RegExp.prototype.test() method to grab a number in a generic string.

RegExp.lastMatch ($&)

RegExp.lastParen ($+)

RegExp.leftContext ($`)

RegExp.rightContext ($')

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This page was last modified on Aug 21, 2026 by MDN contributors.

[Symbol.matchAll]()

[Symbol.replace]()

[Symbol.hasInstance]()

__defineGetter__()

__defineSetter__()

__lookupGetter__()

__lookupSetter__()

propertyIsEnumerable()