Javascript Articles - Page 281 of 671

Suppose we have an array that contains duplicate elements like this −const arr = [1, 1, 2, 2, 3, 4, 4, 5];We are required to write a JavaScript function that takes in one such array and returns a new array. The array should only contain the elements that only appear once in the original array.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [1, 1, 2, 2, 3, 4, 4, 5]; const extractUnique = arr => {    const res = [];    for(let i = 0; i < arr.length; i++){   ... Read More

We are required to write a JavaScript function that takes in an array of numbers.The function should return the sum of all the prime numbers present in the array.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [43, 6, 6, 5, 54, 81, 71, 56, 8, 877, 4, 4]; const isPrime = n => {    if (n===1){       return false;    }else if(n === 2){       return true;    }else{       for(let x = 2; x < n; x++){          if(n % ... Read More

We are required to write a JavaScript function that takes in a string that may contain some backward slashes.And the function should return a new string where all the backslashes with forward slashes.Therefore, let’s write the code for this function −ExampleThe code for this will be −const str = 'Th/s str/ng /conta/ns some/ forward slas/hes'; const invertSlashes = str => {    let res = '';    for(let i = 0; i < str.length; i++){       if(str[i] !== '/'){          res += str[i];          continue;       };       ... Read More

We are required to write a JavaScript function that takes in a string and checks whether it is sorted or not.For example:isSorted('adefgjmxz') // true isSorted('zxmfdba') // true isSorted('dsfdsfva') // falseTherefore, let’s write the code for this function −ExampleThe code for this will be −const str = 'abdfhlmxz'; const findDiff = (a, b) => a.charCodeAt(0) - b.charCodeAt(0); const isStringSorted = (str = '') => {    if(str.length < 2){       return true;    };    let res = ''    for(let i = 0; i < str.length-1; i++){       if(findDiff(str[i+1], str[i]) > 0){         ... Read More

Suppose we have an array of objects like this −const array = [    {key: 'a', value: false},    {key: 'a', value: 100},    {key: 'a', value: null},    {key: 'a', value: 23} ];We are required to write a JavaScript function that takes in one such array and places all the objects that have falsy values for the "value" property to the bottom and sorts all other objects in decreasing order by the "value" property.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [    {key: 'a', value: false},    {key: 'a', ... Read More

We are required to write a JavaScript function that takes in a string which contains English alphabets. The function should return an object containing the count of vowels and consonants in the string.Therefore, let’s write the code for this function −ExampleThe code for this will be −const str = 'This is a sample string, will be used to collect some data'; const countAlpha = str => {    return str.split('').reduce((acc, val) => {       const legend = 'aeiou';       let { vowels, consonants } = acc;       if(val.toLowerCase() === val.toUpperCase()){         ... Read More

We are required to write a JavaScript function that takes in an array of numbers as the first argument and a single number as the second argument. The function should return an array of all the elements from the input array that are greater than or equal to the number taken as the second argument.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [56, 34, 2, 7, 76, 4, 45, 3, 3, 34, 23, 2, 56, 5]; const threshold = 40; const findGreater = (arr, num) => {    const res = ... Read More

Suppose we have two arrays −const keys = [0, 4, 2, 3, 1]; const values = ["first", "second", "third", "fourth", "fifth"];We are required to write a JavaScript function that takes in the keys and the values array and maps the values to the corresponding keys.Therefore, the output should look like −const map = {    0 => 'first',    4 => 'second',    2 => 'third',    3 => 'fourth',    1 => 'fifth' };Therefore, let’s write the code for this function −ExampleThe code for this will be −const keys = [0, 4, 2, 3, 1]; const values = ["first", ... Read More

The given there is an array and the task is to convert an array of objects to an object. Input-Output Scenario Let’s look into an input-output scenario of converting the array objects into an object. Consider there is an array having objects in it. Now, we need to convert those array objects into a single JSON object. Const Arr = [ {1:'one'}, {2:'two'} ]; Output = { "1":"one", "2":"two" }; //Object Using Object.assign() The ... Read More

The Hex (Hexadecimal) code is a six-digit code and a three-byte hexadecimal number that is used to represent the colors. These three bytes represent RGB which means the amount of red, green, and blue in a particular shade of a color. Each byte will represent a number in the range 00 to FF (Hexadecimal notation) or 0 to 255 in decimal notation. This indicates the intensity of each of the color components from 0 to 255. The following are the functions to be used for generating random hex codes − Math.random() is used to get the number randomly in the ... Read More