Found 8591 Articles for Front End Technology

Implementing Math function and return m^n in JavaScript

AmitDiwan
Updated on 23-Nov-2020 06:32:14

187 Views

We are required to write a JavaScript function that takes in two numbers say m and n. Then function should calculate and return m^n.For example − For m = 4, n = 3, thenpower(4, 3) = 4^3 = 4 * 4 * 4 = 64 power(6, 3) = 216The code for this will be the following using the power() function in JavaScript −Exampleconst power = (m, n) => {    if(n < 0 && m !== 0){       return power(1/m, n*-1);    };    if(n === 0){       return 1;    }    if(n === 1){       return m;    };    if (n % 2 === 0){       const res = power(m, n / 2);       return res * res;    }else{       return power(m, n - 1) * m;    }; }; console.log(power(4, 3)); console.log(power(6, 3));OutputAnd the output in the console will be −64 216

JavaScript checking if all the elements are same in an array

Alshifa Hasnain
Updated on 06-Mar-2025 19:21:59

501 Views

In this article, we will learn to check if all the elements are the same in an array in JavaScript. Finding all elements of an array to be the same is a frequent problem in JavaScript, usually needed for data validation, game logic, and algorithm building. Problem Statement We are required to write a JavaScript function that takes in an array of literals. The function should find whether or not all the values in the array are the same. If they are the same, the function should return true, or false otherwise. For Example Input const arr2 = [1, 1, ... Read More

JavaScript: compare array element properties, and if identical, combine

AmitDiwan
Updated on 23-Nov-2020 06:29:29

96 Views

Suppose, we have an array of objects that contains information about some data storage devices like this −const drives = [    {size:"900GB", count:3},    {size:"900GB", count:100},    {size:"1200GB", count:5},    {size:"900GB", count:1} ];Notice like how the same size comes multiple times.We are required to write a function that takes in one such array and consolidate all repeated sizes into just one single array index and obviously adding up their counts.Exampleconst drives = [    {size:"900GB", count:3},    {size:"900GB", count:100},     {size:"1200GB", count:5},    {size:"900GB", count:1} ]; const groupDrives = (arr = []) => {    const map = ... Read More

Subtracting array in JavaScript Delete all those elements from the first array that are also included in the second array

AmitDiwan
Updated on 23-Nov-2020 06:28:05

149 Views

Suppose, we have two arrays of literals like this −const arr1 = ['uno', 'dos', 'tres', 'cuatro']; const arr2 = ['dos', 'cuatro'];We are required to write a JavaScript function that takes in two such arrays and delete all those elements from the first array that are also included in the second array.Therefore, for these arrays, the output should look like this −const output = ['uno', 'tres'];Exampleconst arr1 = ['uno', 'dos', 'tres', 'cuatro']; const arr2 = ['dos', 'cuatro']; const findSubtraction = (arr1 = [], arr2 = []) => {    let filtered = [];    filtered = arr1.filter(el => {     ... Read More

Best way to flatten an object with array properties into one array JavaScript

AmitDiwan
Updated on 23-Nov-2020 06:26:15

769 Views

Suppose, we have an object of arrays like this −const obj = {    arr_a: [9, 3, 2],    arr_b: [1, 5, 0],    arr_c: [7, 18] };We are required to write a JavaScript function that takes in one such object of arrays. The function should construct an flattened and merged array based on this object.Therefore, the final output array should look like this −const output = [9, 3, 2, 1, 5, 0, 7, 18];Exampleconst obj = {    arr_a: [9, 3, 2],    arr_b: [1, 5, 0],    arr_c: [7, 18] }; const objectToArray = (obj = {}) => {    const res = [];    for(key in obj){       const el = obj[key];       res.push(...el);    };    return res; }; console.log(objectToArray(obj));OutputAnd the output in the console will be −[    9, 3, 2, 1,    5, 0, 7, 18 ]

Construct objects from joining two strings JavaScript

AmitDiwan
Updated on 23-Nov-2020 06:25:04

318 Views

We are required to write a JavaScript function that takes in two comma separated strings. The first string is the key string and the second string is the value string, the number of elements (commas) in both the strings will always be the same.Our function should construct an object based on the key and value strings and map the corresponding values to the keys.Exampleconst str1= '[atty_hourly_rate], [paralegal_hourly_rate], [advanced_deposit]'; const str2 = '250, 150, 500'; const mapStrings = (str1 = '', str2 = '') => {    const keys = str1.split(', ').map( (a) => {       return a.slice(1, -1); ... Read More

Convert 2d tabular data entries into an array of objects in JavaScript

AmitDiwan
Updated on 23-Nov-2020 06:23:50

167 Views

Suppose, we have an array of arrays like this −const arr = [    ["Ashley", "2017-01-10", 80],    ["Ashley", "2017-02-10", 75],    ["Ashley", "2017-03-10", 85],     ["Clara", "2017-01-10", 90],    ["Clara", "2017-02-10", 82] ];We are required to write a JavaScript function that takes in one such array as the first and the only input.The function should then construct a new array of objects based on the input array. The array should contain an object for each unique subarray of the input array. (by unique, in this context, we mean the subarray that have their first element unique).Each object must ... Read More

Filtering array within a limit JavaScript

AmitDiwan
Updated on 23-Nov-2020 06:21:52

709 Views

We are required to write a JavaScript function that takes in an array of numbers as the first argument and an upper limit and lower limit number as second and third argument respectively. Our function should filter the array and return a new array that contains elements between the range specified by the upper and lower limit (including the limits)Exampleconst array = [18, 23, 20, 17, 21, 18, 22, 19, 18, 20]; const lower = 18; const upper = 20; const filterByLimits = (arr = [], upper, lower) => {    let res = [];    res = arr.filter(el => {       return el >= lower && el

Map multiple properties in array of objects to the same array JavaScript

AmitDiwan
Updated on 23-Nov-2020 06:20:29

1K+ Views

Suppose, we have an array of objects like this −const arr = [    {a: 1, b: 2},    {a: 3, b: 4},    {a: 5, b: 6} ];We are required to write a JavaScript function that takes in one such array of objects. The function should then map this array to an array of Number literals like this −const output = [1, 2, 3, 4, 5, 6];Exampleconst arr = [    {a: 1, b: 2},    {a: 3, b: 4},    {a: 5, b: 6} ]; const pushToArray = (arr = []) => {    const result = arr.reduce((acc, obj) => {     acc.push(obj.a);    acc.push(obj.b);    return acc; }, []);    return result; }; console.log(pushToArray(arr));OutputAnd the output in the console will be −[ 1, 2, 3, 4, 5, 6 ]

How to sort a JavaScript object list based on a property when the property is not consistent

AmitDiwan
Updated on 23-Nov-2020 06:19:17

118 Views

We have an array that contains various objects. A few objects on this array have a date field (which basically is returned as a string from the server, not a date object), while for others this field is null.The requirement is that we have to display objects without date at top, and those with date needs to be displayed after them sorted by date field.Also, for objects without date sorting needs to be done alphabetically.Exampleconst sorter = ((a, b) => {    if (typeof a.date == 'undefined' && typeof b.date != 'undefined') {       return -1;    } ... Read More

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