Javascript Articles - Page 231 of 607

We are required to write a JavaScript function that takes in an array of literal values. Our function should pick all those values from the array that appears exactly twice in the array and return a new array of those elements.ExampleThe code for this will be −const arr = [0, 1, 2, 2, 3, 3, 5]; const findAppearances = (arr, num) => {    let count = 0;    for(let i = 0; i < arr.length; i++){       const el = arr[i];       if(num !== el){          continue;       };   ... Read More

Suppose, we have two different array of objects that contains information about the questions answered by some people −const arr1=[    { PersonalID: '11', qusetionNumber: '1', value: 'Something' },    { PersonalID: '12', qusetionNumber: '2', value: 'whatever' },    { PersonalID: '13', qusetionNumber: '3', value: 'anything' },    { PersonalID: '14', qusetionNumber: '4', value: 'null' } ]; const arr2=[    { qusetionNumber: '2', chID: '111', cValue: 'red' },    { qusetionNumber: '2', chID: '112', cValue: 'green'},    { qusetionNumber: '2', chID: '113', cValue: 'blue' },    {qusetionNumber: '3', choiceID: '114', cValue: 'yellow'},    {qusetionNumber: '4', choiceID: '115', cValue: 'red'} ];We ... Read More

We are required to write a JavaScript function that takes in a multidimensional array of arrays of literal values. Our function should return the intersecting array of all the subarrays present in the input array.ExampleThe code for this will be −const arr = [    ["garden","canons","philips","universal"],    ["universal","ola","uber","bangalore"] ]; const findMultiIntersection = (arr = []) => {    const res = [];    arr.forEach(el => {       const thisObj = this;       el.forEach(element => {          if(!thisObj[element]){             thisObj[element] = true;          }          else{             res.push(element)          };       });    }, {});    return res; }; console.log(findMultiIntersection(arr));OutputAnd the output in the console will be −[ 'universal' ]

Suppose we have two arrays of literals like these −const arr1= ['a', 'b', 'c']; const arr2= ['d', 'e', 'f'];We are required to write a JavaScript function that takes in two such arrays and build all possible combinations from the arrays.So, for these two arrays, the output should look like −const output = [ad, ae, af, bd, be, bf, cd, ce, cf];ExampleThe code for this will be −const arr1= ['a', 'b', 'c']; const arr2= ['d', 'e', 'f']; const combineArrays = (...arr) => {    const res = [];    const combinePart = (part, index) => {       arr[index].forEach(el => ... Read More

Suppose, we have an array that contains dates in MM-YYYY format like this −const arr = ["1-2016", "7-2015", "7-2016", "3-2016", "8-2016", "2-2016", "6-2016", "8-2015", "5-2016", "4-2016", "9-2015", "10-2015", "11-2015", "12-2015"];We are required to write a JavaScript function that takes in one such array and sorts it such that the dates in the array are arranged in oldest to newest order.ExampleThe code for this will be −const arr = ["1-2016", "7-2015", "7-2016", "3-2016", "8-2016", "2-2016", "6-2016", "8-2015", "5-2016", "4-2016", "9-2015", "10-2015", "11-2015", "12-2015"]; const padToString = (num) => {    return String("0" + num).slice(-2); }; const sortByDate = (first, second) => ... Read More

We are required to write a JavaScript function that takes in an array of literals and finds the most frequent number in the array and how many times it is repeated.ExampleThe code for this will be −const arr = ['13', '4', '1', '1', '4', '2', '3', '4', '4', '1', '2', '4', '9', '3']; const findFrequency = (arr = []) => {    const count = {};    const max = arr.reduce((acc, val, ind) => {       count[val] = (count[val] || 0) + 1;       if (!ind || count[val] > count[acc[0]]) {          return ... Read More

We are required to write a JavaScript function that determines how many different ways we can remove a group of values from a sequence, leaving the original sequence in order (stable), and making sure to remove only one instance value each from the original sequence.For example − If the sequence array is −const arr = [1, 2, 1, 3, 1, 4, 4];And the array to be removed is −const arr2 = [1, 4, 4];Then there are three possible ways of doing this without disrupting the order of elements −1 --> [2, 1, 3, 1] 2 --> [1, 2, 3, 1] ... Read More

Suppose, we have an array of objects like this −const arr = [{ 'title': 'Hey',    'foo': 2,    'bar': 3 }, {    'title': 'Sup',    'foo': 3,    'bar': 4 }, {    'title': 'Remove',    'foo': 3,    'bar': 4 }];We are required to write a JavaScript function that takes in one such array as the first input and an array of string literals as the second input.Our function should then prepare a new array that contains all those objects whose title property is partially or fully included in the second input array of literals.ExampleThe code for ... Read More

Suppose, we have an array string that contains some duplicate entries like this −const arr = ['California', 'Texas', 'Texas', 'Texas', 'New York', 'Missouri', 'New Mexico', 'California'];We are required to write a JavaScript function that takes in one such array. Our function should then construct an array of objects that contains an object for each unique entry and a property "count" that contains its count in the original array.Therefore, the final output for the above array should look something like this −const output = [    {'name':'California', 'count':2},    {'name':'Texas', 'count':3},    {'name':'New York', 'count':1},    {'name':'Missouri', 'count':1},    {'name':'New Mexico', ... Read More

Suppose, we have one array of strings and another array of objects like this −const arr1 = [ '1956888670', '2109171907', '298845084' ]; const arr2 = [    { KEY: '1262875245', VALUE: 'Vijay Kumar Verma' },    { KEY: '1956888670', VALUE: 'Sivakesava Nallam' },    { KEY: '2109171907', VALUE: 'udm analyst' },    { KEY: '298845084', VALUE: 'Mukesh Nagora' },    { KEY: '2007285563', VALUE: 'Yang Liu' },    { KEY: '1976156380', VALUE: 'Imtiaz Zafar' }, ];We are required to write a JavaScript function that takes in two such arrays. Then our function should return a filtered version of the second ... Read More