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 ⁨January 2020⁩.

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
Writableno
Enumerableno
Configurableno

Examples

js
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® 2026 Language Specification
# sec-symbol.search

Browser compatibility

See also