Collect.js | crossJoin() Method

Collect.js is a fluent and convenient wrapper for working with arrays and objects. The JavaScript array is first transformed into a collection and then the function is applied to the collection. The crossJoin() method cross joins the collection with an array or collection and return all possible permutations between them. Installation:

• Collect.js can be installed via NPM:

  npm install --save collect.js

• You can also use CDN of collect.js

  <script src="https://cdnjs.com/libraries/collect.js"></script>

Syntax:

collect(array1).crossJoin(array2)

Parameters: The collect() takes one argument that is converted into the collection and then crossJoin() function also take an array. Return Value: Returns an array with all possible permutation of between them. Below example illustrate the crossJoin() method in JavaScript: Example: Here collect = require('collect.js') is used to import the collect.js library into the file. javascript

const collect = require('collect.js');

let numbers = [1, 2, 3, 4]

let alphabets = ['a', 'b', 'c', 'd']

// covert into collection
const collection = collect(numbers);

const permutations = collection.crossJoin(alphabets)

// returning the permutations
let arr =  permutations.all();

console.log("Permutations: ", arr);

Output