Collect.js contains() Method

The contains() method is used to determines whether the collection contains a given item or not. If it contains the item then it returns true otherwise false. The JavaScript array is first transformed into a collection and then the function is applied to the collection.

Syntax:  

collect(array).contains(item)

Parameters: This method accepts single parameter i.e. converted into the collection and then contains() function take an item to be searched.

Return Value: Returns a boolean value.

Below examples illustrate the contains() method in Collect.js:

Example 1: Here collect = require(‘collect.js’) is used to import the collect.js library into the file.

Javascript

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

let arr = [1, 2, 3];

// Convert array into collection
const collection = collect(arr);

// item to searched
let item = 3;

let newObject = collection.contains(item);

console.log("Result : ", newObject);

Output:

Result :  true

Example 2:

Javascript

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

let arr = [1, 2, 3]

// Convert array into collection
const collection = collect(arr);

// concat the array
let concatarr = collection.concat(['a', 'b', 'c']);

// concat the object
concatarr = concatarr.concat({ first : "GeeksforGeeks",
        second : "Collect.js"});

// item to searched
let item = "GeeksforGeek";

let newObject = collection.contains(item);

console.log("Result : ", newObject);

Output:

Result : false

Reference: https://collect.js.org/api/contains.html