Javascript Articles - Page 229 of 607

We are required to write a JavaScript function that takes in an array of Numbers as the first argument and a number, say n, as the second argument.Our function should then pick the n greatest numbers from the array and return a new array consisting of those numbers.ExampleThe code for this will be −const arr = [3, 4, 12, 1, 0, 5, 22, 20, 18, 30, 52]; const pickGreatest = (arr = [], num = 1) => {    if(num > arr.length){       return [];    };    const sorter = (a, b) => b - a;   ... Read More

We are required to write a JavaScript function that takes in an array of literal values.The array might contain some repeating values.Our function should remove all the values from the array that are repeating. We are required to remove all instances of all such elements.ExampleThe code for this will be −const arr = [1, 2, 3, 2, 4]; const removeAllInstances = (arr = []) => {    filtered = arr.filter(val => {       const lastIndex = arr.lastIndexOf(val);       const firstIndex = arr.indexOf(val);       return lastIndex === firstIndex;    });    return filtered; }; console.log(removeAllInstances(arr));OutputAnd the output in the console will be −[ 1, 3, 4 ]

Suppose, we have an array of objects that contains data about some students like this −const arr = [{    name: 'A',    idNo: 1,    marks: {       math: 98,       sci: 97,       eng: 89    } }, {    name: 'B',    idNo: 2,    marks: {       math: 88,       sci: 87,       eng: 79    } }, {    name: 'C',    idNo: 3,    marks: {       math: 87,       sci: 98,       eng: 91   ... Read More

In this article, we will learn to build a JavaScript function that calculates the complementary color for a given hex color code. In web development working with colors and their relationships is an essential aspect of design and user interface. One of the concepts that designers often use is complementary colors—colors that are opposite each other on the color wheel, providing contrast and enhancing the visual appeal.You can try our Online Color Picker Tool to create new colors. Understanding Complementary Colors The following is the knowledge through which we understand complementary colors − Complementary ... Read More

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