Symbol.search

Baseline Widely available

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

The Symbol.search static data property represents the well-known symbol Symbol.search. The String.prototype.search() method looks up this symbol on its first argument for the method that returns the index within a string that matches the current object.

For more information, see RegExp.prototype[Symbol.search]() and String.prototype.search().

Try it

class Search1 {
  constructor(value) {
    this.value = value;
  }
  [Symbol.search](string) {
    return string.indexOf(this.value);
  }
}

console.log("foobar".search(new Search1("bar")));
// Expected output: 3

Value

The well-known symbol Symbol.search.

Property attributes of `Symbol.search`
Writable	no
Enumerable	no
Configurable	no

Examples

Custom string search

class CaseInsensitiveSearch {
  constructor(value) {
    this.value = value.toLowerCase();
  }
  [Symbol.search](string) {
    return string.toLowerCase().indexOf(this.value);
  }
}

console.log("foobar".search(new CaseInsensitiveSearch("BaR"))); // 3

Specifications

Specification
ECMAScript® 2027 Language Specification # sec-symbol.search

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
`search`	50	79	49	37	10	50	49	37	10	5.0	50	10	1.0.0	1.0	6.0.0