RegExp.prototype[@@search]()

The [@@search]() method executes a search for a match between a this regular expression and a string.

str

A String that is a target of the search.

integer

If successful, [@@search]() returns the index of the first match of the regular expression inside the string. Otherwise, it returns -1.

This method is called internally in String.prototype.search(). For example, the following two examples return the same result.

'abc'.search(/a/);

/a/[Symbol.search]('abc');

This method exists for customizing the search behavior in RegExp subclasses.

This method can be used in almost the same way as String.prototype.search(), except the different this and the different arguments order.

var re = /-/g;
var str = '2016-01-02';
var result = re[Symbol.search](str);
console.log(result);  // 4

Subclass of RegExp can override [@@search]() method to modify the behavior.

class MyRegExp extends RegExp {
  constructor(str) {
    super(str)
    this.pattern = str;
  }
  [Symbol.search](str) {
    return str.indexOf(this.pattern);
  }
}

var re = new MyRegExp('a+b');
var str = 'ab a+b';
var result = str.search(re); // String.prototype.search calls re[@@search].
console.log(result); // 3

• Polyfill of RegExp.prototype[@@search] in core-js
• String.prototype.search()
• RegExp.prototype[@@match]()
• RegExp.prototype[@@replace]()
• RegExp.prototype[@@split]()
• RegExp.prototype.exec()
• RegExp.prototype.test()