Suppose, we have an array of objects like this −const arr = [    {area: 'NY', name: 'Bla', ads: true},    {area: 'DF', name: 'SFS', ads: false},    {area: 'TT', name: 'SDSD', ads: true},    {area: 'SD', name: 'Engine', ads: false},    {area: 'NSK', name: 'Toyota', ads: false}, ];We are required to write a JavaScript function that takes in one such array as the first argument and an array of string literals as the second argument.Our function should then filter the input array of objects to contain only those objects whose "area" property is included in the array of literals ... Read More

Suppose, we have some data regarding some images in an array like this −const arr = [{    'image': "jv2bcutaxrms4i_img.png",    'gallery_image': true }, {    'image': "abs.png",    'gallery_image': true }, {    'image': "acd.png",    'gallery_image': false }, {    'image': "jv2bcutaxrms4i_img.png",    'gallery_image': true }, {    'image': "abs.png",    'gallery_image': true }, {    'image': "acd.png",    'gallery_image': false }];We are required to write a JavaScript function that takes in one such array.Our function should remove the objects from the array that have duplicate values for the 'image' property.ExampleThe code for this will be −const arr ... Read More

Suppose, we have an array of values like this −const arr = [    {       value1:[1, 2],       value2:[{type:'A'}, {type:'B'}]    },    {       value1:[3, 5],       value2:[{type:'B'}, {type:'B'}]    } ];We are required to write a JavaScript function that takes in one such array. Our function should then prepare an array where the data is grouped according to the "type" property of the objects.Therefore, for the above array, the output should look like −const output = [    {type:'A', value: [1, 2]},    {type:'B', value: [3, 5]} ];ExampleThe code ... Read More

In this article, we will learn to count the number of undefined elements in an array using JavaScript. When working with arrays in JavaScript, you may encounter situations where certain elements are either explicitly set as undefined or are missing altogether (often represented by empty slots in sparse arrays). Problem Statement Given an array that may contain undefined values, we need to count how many elements in the array are defined (i.e., not undefined).  Input const arr = [12, undefined, "blabla", , true, 44]; Output 44 elements are defined (12, "blabla", true, and 44). Thus, the expected output is ... Read More

Suppose, we have two arrays like these −const meals = ["breakfast", "lunch", "dinner"]; const ingredients = [    ["eggs", "yogurt", "toast"],    ["falafel", "mushrooms", "fries"],    ["pasta", "cheese"] ];We are required to write a JavaScript function that takes in two such arrays and maps the subarrays in the second array to the corresponding strings of the first array.Therefore, the output for the above arrays should look like −const output = {    "breakfast" : ["eggs", "yogurt", "toast"],    "lunch": ["falafel", "mushrooms", "fries"],    "dinner": ["pasta", "cheese"] };ExampleThe code for this will be −const meals = ["breakfast", "lunch", "dinner"]; const ingredients ... Read More

We are required to write a JavaScript function that takes in two arrays of the same length.Our function should then combine corresponding elements of the arrays, to form the corresponding subarray of the output array, and then finally return the output array.If the two arrays are −const arr1 = ['a', 'b', 'c']; const arr2 = [1, 2, 3];Then the output should be −const output = [    ['a', 1],    ['b', 2],    ['c', 3] ];ExampleThe code for this will be −const arr1 = ['a', 'b', 'c']; const arr2 = [1, 2, 3]; const combineCorresponding = (arr1 = [], arr2 ... Read More

Suppose, we have a nested array of objects like this −const arr = [    { value: 'some value' },    {       array: [          { value: 'some value' },          {             array: [                { value: 'some value' },                { value: 'some value' },             ],          },          { value: 'some value' },          {   ... Read More

Suppose, we have a nested array like this −const arr = ['zero', ['one', 'two' , 'three', ['four', ['five', 'six', ['seven']]]]];We are required to write a JavaScript function that takes in a nested array. Our function should then return a string that contains all the array elements joined by a semicolon (';')Therefore, for the above array, the output should look like −const output = 'zero;one;two;three;four;five;six;seven;';ExampleThe code for this will be −const arr = ['zero', ['one', 'two' , 'three', ['four', ['five', 'six', ['seven']]]]]; const buildString = (arr = [], res = '') => {    for(let i = 0; i < arr.length; ... Read More

Suppose, we have an array of objects like this −const arr = [    { id : "23", name : "Item 1", isActive : true},    { id : "25", name : "Item 2", isActive : false},    { id : "26", name : "Item 3", isActive : false},    { id : "30", name : "Item 4", isActive : true},    { id : "45", name : "Item 5", isActive : true} ];We are required to write a JavaScript function that takes in one such object and return an array of the value of "id" property of all those ... Read More

We are required to write a JavaScript function that takes in an array of literal values as the first argument and a string as the second argument.Our function should sort the array alphabetically but keeping the string provided as the second argument (if it exists in the array) as the first element, irrespective of the text it contains.ExampleThe code for this will be −const arr = ["Apple", "Orange", "Grapes", "Pineapple", "None", "Dates"]; const sortKeepingConstants = (arr = [], text = '') => {    const sorter = (a, b) => {       return (b === text) - (a ... Read More