JS: Iterator.prototype.take

By Xah Lee. Date: .

(new in ECMAScript 2025)

iterator.take(n)
  • Take the first n yield of iterator.
  • Return a new Generator.

Normally you can use this method on any Iterable, because all standard iterable objects are also Iterator.

// define a generator function
function* gf() {
  for (let x of [1, 2, 3, 4, 5]) yield x;
}

console.log(
  JSON.stringify(Array.from(
    gf().take(3),
  )) === `[1,2,3]`,
);
// true

// is iterable
console.log(Reflect.has(gf().take(3), Symbol.iterator));
// true

// is iterator
console.log(Reflect.has(gf().take(3), "next"));
// true