JS: Set.prototype.entries

By Xah Lee. Date: . Last updated: .

(new in ECMAScript 2015)

mySet.entries()
  • Return a Generator.
  • Each yield is a array of the form [value, value].
const xx = new Set([3, 4]);
for (let [k, v] of xx.entries()) {
 console.log(k, v);
}
// 3 3
// 4 4

Verify Result is a Generator

// verify the result is iterator and iterable

const xx = (new Set([3, "yes"])).entries();

// is iterable
console.assert(Reflect.has(xx, Symbol.iterator));

// is iterator
console.assert(Reflect.has(xx, "next"));