RegExp.prototype[Symbol.split]()

The Symbol.split method of RegExp instances specifies how String.prototype.split should behave when the regular expression is passed in as the separator.

This method exists for customizing the behavior of split() in RegExp subclasses. It is called internally in String.prototype.split() when a RegExp is passed as the separator. For example, the following two examples return the same result.

Like [Symbol.matchAll](/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/Symbol.matchAll), Symbol.split starts by using [[Symbol.species]](/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/Symbol.species) to construct a new regex, thus avoiding mutating the original regexp in any way. The constructor receives this and the original flags, plus the y (“sticky”) flag if it was not originally present. The g (“global”) flag is irrelevant for the method’s behavior. By default, due to the RegExp() constructor’s behavior, lastIndex starts as 0.

Syntax example: regexp[Symbol.split](str)