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RegExp.prototype.ignoreCase

The ignoreCase accessor property indicates whether or not the i flag is used with the regular expression.

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Description

RegExp.prototype.ignoreCase has the value true if the i flag was used; otherwise, false. The i flag indicates that case should be ignored while attempting a match in a string.

If the regex has the unicode flag, the case mapping happens as specified in CaseFolding.txt. Otherwise, case mapping uses the Unicode Default Case Conversion — the same algorithm used in String.prototype.toUpperCase() and String.prototype.toLowerCase().

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

Examples

Using ignoreCase

const regex = /foo/i;

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

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
ignoreCase
1
12
1
5.5
5
1
4.4
18
4
10.1
1
1.0
1.0
0.10.0
prototype_accessor
48
12
38
5.5
35
1.3
48
48
38
35
1
5.0
1.0
6.0.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/ignoreCase