Found 9326 Articles for Object Oriented Programming

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

Suppose, we have two child and parent JSON arrays of objects like these −const child = [{    id: 1,    name: 'somename',    parent: {       id: 2    }, }, {    id: 2,    name: 'some child name',    parent: {       id: 4    } }]; const parent = [{    id: 1,    parentName: 'The first',    child: {} }, {    id: 2,    parentName: 'The second',    child: {} }, {    id: 3,    parentName: 'The third',    child: {} }, {    id: 4,    parentName: 'The ... Read More

Suppose we have a sorted array of numbers like this where we can have consecutive numbers.const arr = [1, 2, 3, 5, 7, 8, 9, 11];We are required to write a JavaScript function that takes one such array.Our function should form a sequence for this array. The sequence should be such that for all the consecutive elements of the array, we have to just write the starting and ending numbers replacing the numbers in between with a dash (-), and keeping all other numbers unchanged.Therefore, for the above array, the output should look like −const output = '1-3, 5, 7-9, ... Read More

Suppose, we have an array of objects like this −const arr = [    {"Date":"2014", "Amount1":90, "Amount2":800},    {"Date":"2015", "Amount1":110, "Amount2":300},    {"Date":"2016", "Amount1":3000, "Amount2":500} ];We are required to write a JavaScript function that takes in one such array and maps this array to another array that contains arrays instead of objects.Therefore, the final array should look like this −const output = [    ['2014', 90, 800],    ['2015', 110, 300],    ['2016', 3000, 500] ];ExampleThe code for this will be −const arr = [    {"Date":"2014", "Amount1":90, "Amount2":800},    {"Date":"2015", "Amount1":110, "Amount2":300},    {"Date":"2016", "Amount1":3000, "Amount2":500} ]; const arrify ... Read More

Suppose, we have a comma-separated string like this −const str = "a, b, c, d , e";We are required to write a JavaScript function that takes in one such and sheds it off all the whitespaces it contains.Then our function should split the string to form an array of literals and return that array.ExampleThe code for this will be −const str = "a, b, c, d , e"; const shedAndSplit = (str = '') => {    const removeSpaces = () => {       let res = '';       for(let i = 0; i < str.length; ... 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 inside it.Our function should remove all the repeating values keeping the first instance of repeating value in the array.ExampleThe code for this will be −const arr = [1, 5, 7, 4, 1, 4, 4, 6, 4, 5, 8, 8]; const deleteDuplicate = (arr = []) => {    for(let i = 0; i < arr.length; ){       const el = arr[i];       if(i !== arr.lastIndexOf(el)){          arr.splice(i, 1);       }       else{          i++;       };    }; }; deleteDuplicate(arr); console.log(arr);OutputAnd the output in the console will be −[ 7, 1, 6, 4, 5, 8 ]

Suppose we have two arrays of objects, the first of which contains some objects with user ids and user names.The array contains objects with user ids and user addresses.The array is −const arr1 = [    {"id":"123", "name":"name 1"},    {"id":"456", "name":"name 2"} ]; const arr2 = [    {"id":"123", "address":"address 1"},    {"id":"456", "address":"address 2"} ];We are required to write a JavaScript function that takes in two such arrays and merges these two arrays to form a third array.The third array should contain the user id, name, and address object of corresponding users.ExampleThe code for this will be −const ... Read More

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