`lazy()`

The lazy method returns a new LazyCollection instance from the underlying array of items.

A lazy collection is backed by a generator, so operations such as map, filter and take are only evaluated as items are pulled — one at a time. This lets you work with very large, or even infinite, data sets while keeping memory usage low, just like Laravel's LazyCollection.

const collection = collect([1, 2, 3, 4, 5]);

collection
  .lazy()
  .filter((number) => number % 2 === 0)
  .map((number) => number * 10)
  .all();

// [20, 40]

You may also create a lazy collection directly from a generator function using LazyCollection.make. Because values are pulled on demand, take short-circuits and never exhausts an infinite source:

import { LazyCollection } from '@h3ravel/collect.js';

LazyCollection
  .make(function* () {
    let number = 1;
    while (true) {
      yield number++;
    }
  })
  .filter((number) => number % 3 === 0)
  .take(2)
  .all();

// [3, 6] — only the first 6 values were ever generated

Call eager() to convert a lazy collection back into a regular Collection.

View source on GitHub

lazy() ​

`lazy()`