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String.prototype.search()

The search() method executes a search for a match between a regular expression and this String object.

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Syntax

search(regexp)

Parameters

regexp

A regular expression object, or any object that has a Symbol.search method.

If regexp is not a RegExp object and does not have a Symbol.search method, it is implicitly converted to a RegExp by using new RegExp(regexp).

Return value

The index of the first match between the regular expression and the given string, or -1 if no match was found.

Description

The implementation of String.prototype.search() itself is very simple — it simply calls the Symbol.search method of the argument with the string as the first parameter. The actual implementation comes from RegExp.prototype[@@search]().

The g flag of regexp has no effect on the search() result, and the search always happens as if the regex's lastIndex is 0. For more information on the behavior of search(), see RegExp.prototype[@@search]().

When you want to know whether a pattern is found, and also know its index within a string, use search().

Examples

The following example searches a string with two different regex objects to show a successful search (positive value) vs. an unsuccessful search (-1).

const str = "hey JudE";
const re = /[A-Z]/;
const reDot = /[.]/;
console.log(str.search(re)); // returns 4, which is the index of the first capital letter "J"
console.log(str.search(reDot)); // returns -1 cannot find '.' dot punctuation

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
search
1
12
1
4
4
1
4.4
18
4
10.1
1
1.0
1.0
0.10.0
flags
No
No
1-49
No
No
No
No
No
4-49
No
No
No
No
No

See also

© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/search