Iterator Helpers

Description

Iterator helpers are exposed by defining new methods on the Iterator object's prototype. These methods align with many functional programming methods you're used to using, such as map, filter, reduce, and other similar methods.

Usage

You could use an iterator helper on the filter method to filter list items by the contents of their innerText property for a collection of DOM nodes, which you can then use later in a for loop:

const posts = document
  .querySelectorAll('ul#specific-list > li')
  .values()
  .filter((item) => item.textContent.includes('kiwi'))
 
// For-of loops can only be used on iterables, which `posts` is!
for (const post of posts) {
  console.log(post.textContent)
}