JS iterator/generator baiscs

iter_gene.js

// Iterator
function nameIterator(names) {
	let nextIndex = 0;
	return {
		next: function () {
			return nextIndex < names.length
				? { value: names[nextIndex++], done: false }
				: { done: true };
		}
	};
}

const namesArr = ['Jack', 'Jill', 'John'];
const names = nameIterator(namesArr);
console.log(names.next());
console.log(names.next());
console.log(names.next());
console.log(names.next());

// ------------------------------------------------

// Generator
function* sayNames() {
	yield 'Jack';
	yield 'Jill';
	yield 'John';
}

const name = sayNames();
console.log(name.next());
console.log(name.next());
console.log(name.next());
console.log(name.next());

// ID Creator
function* createIds() {
	let index = 0;
	while (index < 5) {
		yield index++;
	}
}

const gen = createIds();
console.log(gen.next());
console.log(gen.next());
console.log(gen.next());
console.log(gen.next());
console.log(gen.next());
console.log(gen.next());