arguments[@@iterator]()

The [@@iterator]() method of arguments objects implements the iterable protocol and allows arguments objects to be consumed by most syntaxes expecting iterables, such as the spread syntax and for...of loops. It returns an array iterator object that yields the value of each index in the arguments object.

The initial value of this property is the same function object as the initial value of the Array.prototype.values property (and also the same as Array.prototype[@@iterator]).

arguments[Symbol.iterator]()

function f() {
  for (const letter of arguments) {
    console.log(letter);
  }
}
f("w", "y", "k", "o", "p");