Symbol.replace - JavaScript | MDN (original) (raw)

Baseline

Widely available

The Symbol.replace static data property represents the well-known symbol Symbol.replace. The String.prototype.replace() and String.prototype.replaceAll() methods look up this symbol on their first argument for the method that replaces substrings matched by the current object.

For more information, see RegExp.prototypeSymbol.replace, String.prototype.replace(), and String.prototype.replaceAll().

Try it

class Replace1 {
  constructor(value) {
    this.value = value;
  }
  [Symbol.replace](string) {
    return `s/${string}/${this.value}/g`;
  }
}

console.log("foo".replace(new Replace1("bar")));
// Expected output: "s/foo/bar/g"

Value

The well-known symbol Symbol.replace.

Property attributes of Symbol.replace
Writable no
Enumerable no
Configurable no

Examples

Using Symbol.replace

class CustomReplacer {
  constructor(value) {
    this.value = value;
  }
  [Symbol.replace](string) {
    return string.replace(this.value, "#!@?");
  }
}

console.log("football".replace(new CustomReplacer("foo"))); // "#!@?tball"

Specifications

Specification
ECMAScript® 2026 Language Specification # sec-symbol.replace

Browser compatibility

See also