Symbol.match

The Symbol.match static data property represents the well-known symbol Symbol.match. The String.prototype.match() method looks up this symbol on its first argument for the method used to match an input string against the current object. This symbol is also used to determine if an object should be treated as a regex.

For more information, see RegExp.prototype[Symbol.match](/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/Symbol.match) and String.prototype.match().

This function is also used to identify if objects have the behavior of regular expressions. For example, the methods String.prototype.startsWith(), String.prototype.endsWith() and String.prototype.includes(), check if their first argument is a regular expression and will throw a TypeError if they are. Now, if the match symbol is set to false (or a Falsy value except undefined), it indicates that the object is not intended to be used as a regular expression object.