Collect.js contains() Method Last Updated : 26 Nov, 2022 Summarize Comments Improve Suggest changes Share Like Article Like Report 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 Comment More infoAdvertise with us Next Article Collect.js countBy() Method S SHUBHAMSINGH10 Follow Improve Article Tags : JavaScript Web Technologies Collect.js Similar Reads Collect.js Collect.js is the javascript library for collecting data from tree-based structures. This library is used on JavaScript Array and Objects. Collect.js TutorialWhy Collect.js? It is a fluent and convenient wrapper for working with arrays and objects. It provides us with different functions that help i 1 min read Collect.js Introduction Collect.js is a JavaScript library for collecting data from tree-based structures. This library is used on JavaScript Array and Objects. Features: Some of the important features of Collect.js are: It is a fluent and convenient wrapper for working with arrays and objects.It provides us with different 2 min read Collect.js | all() Method The all() method is used to return the underlying array or object represented by the collection. The JavaScript array is first transformed into a collection and then the function is applied to the collection. Syntax: collect(array).all() Parameters: The method does not accept any parameter. Return 1 min read Collect.js average() Method The average() method is used to return the average of all the items in a collection. This method is an alias of avg() method. Syntax: collect(array).average() Parameters: The collect() method takes one argument that is converted into the collection and then average() function is applied on it, which 1 min read Collect.js | avg() 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 avg() method returns the average of all the items in a collection. Installation: Collect.js can be in 2 min read Collect.js | collapse() 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 collapse() method convert collection of arrays into a single flat array. Installation: Collect.js can 2 min read Collect.js | combine() 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 combine() method combines two different arrays with keys-values. Installation:  Collect.js can be in 1 min read Collect.js concat() Method The concat() method is used to return the merged arrays or objects represented by the collection. The JavaScript array is first transformed into a collection and then the function is applied to the collection. Syntax: collect(array1).concat(array2) Parameters: The collect() method takes one argument 2 min read 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).cont 2 min read Collect.js countBy() Method The countBy() method is used to count the occurrence of values in the collection. This method counts the occurrence of every element. Syntax: collect(array).countBy() Parameters: The collect() method takes one argument that is converted into the collection and then countBy() method is applied on it. 1 min read Like