Found 8591 Articles for Front End Technology

Code to construct an object from a string in JavaScript

AmitDiwan
Updated on 17-Oct-2020 09:14:18

269 Views

We are required to write a function that takes in a string as the first and the only argument and constructs an object with its keys based on the unique characters of the string and value of each key being defaulted to 0.For example: If the input string is −const str = 'hello world!';OutputThen the output object should be −const obj = { "h": 0, "e": 0, "l": 0, "o": 0, " ": 0, "w": 0, "r": 0, "d": 0, "!": 0 };ExampleLet’s write the code for this function −const str = 'hello world!'; const stringToObject = str => { ... Read More

Finding place value of a number in JavaScript

AmitDiwan
Updated on 17-Oct-2020 09:13:31

805 Views

We are required to write a function, let’s say splitNumber() that takes in a positive integer and returns an array populated with the place values of all the digits of the number.For example −If the input number is −const num = 1234;OutputThen the output should be −const output = [1000, 200, 30, 4];Let’s write the code for this function.This problem is very suitable for a recursive approach as we will be iterating over each digit of the number.Therefore, the recursive function that returns an array of respective place values of digits will be given by −Exampleconst splitNumber = (num, arr ... Read More

Rounding off numbers to some nearest power in JavaScript

AmitDiwan
Updated on 17-Oct-2020 09:08:38

168 Views

We are required to write a JavaScript function that takes in a number and returns a number that can be represented as a power of 2 which is nearest to the input number.For example: If the input number if 145.Then the output should be 128 because 145 is the nearest such number to 128 which can be represented as 2^n for some whole number value of n.ExampleThe code for this will be −const num = 145; const nearestPowerOfTwo = num => {    // dealing only with non negative numbers    if(num < 0){       num *= -1; ... Read More

Searching for a query using binary search in JavaScript

AmitDiwan
Updated on 17-Oct-2020 09:03:37

194 Views

We are required to write a JavaScript function that takes in a sorted array of literals as the first argument and a query literal as second. Then our function should make use of the Binary Search algorithm to find whether the query exists in the array or not.If it exists, we return its index in the array, otherwise we return -1.ExampleThe code for this will be −const arr = [1, 2, 3, 5, 6, 7, 10, 11, 14, 15, 17, 19, 20, 22, 23]; const binarySearch = (arr, query) => {    let index = Math.floor(arr.length / 2);    if ... Read More

Computing zeroes (solutions) of a mathematical equation in JavaScript

AmitDiwan
Updated on 17-Oct-2020 09:01:46

109 Views

We are required to write a JavaScript function that takes in three numbers (representing the coefficient of quadratic term, coefficient of linear term and the constant respectively in a quadratic quadratic).And we are required to find the roots, (if they are real roots) otherwise we have to return false.ExampleThe code for this will be −const coeff = [1, 12, 3]; const findRoots = co => {    const [a, b, c] = co;    const discriminant = (b * b) - 4 * a * c;    // non real roots    if(discriminant < 0){       return false; ... Read More

Keeping only redundant words in a string in JavaScript

AmitDiwan
Updated on 17-Oct-2020 08:59:48

413 Views

We are required to write a JavaScript function that takes in a string and returns a new string with only the words that appeared for more than once in the original string.For example:If the input string is −const str = 'this is a is this string that contains that some repeating words';OutputThen the output should be −const output = 'this is that';Let’s write the code for this function −ExampleThe code for this will be −const str = 'this is a is this string that contains that some repeating words'; const keepDuplicateWords = str => {    const strArr = str.split(" ... Read More

Program to implement Bucket Sort in JavaScript

AmitDiwan
Updated on 15-Oct-2020 09:37:17

675 Views

The Bucket Sort works by splitting the array of size n into k buckets which holds a specific range of element values.Then, these buckets are then sorted using a sorting algorithm which can be chosen based on the expected input size.We can describe this algorithm as follows −Algorithm:Create the initial bucketSort function Create variables for i, min, max, and bucket size Find min and max value Create amount of buckets Push values to correct buckets Sort bucketsExampleThe code for this will be −const arr = [32, 6, 34, 4, 78, 1, 6767, 4, 65, 34, 879, 7]; const bucketSort = ... Read More

Algorithm for matrix multiplication in JavaScript

AmitDiwan
Updated on 15-Oct-2020 09:34:04

2K+ Views

We are required to write a JavaScript function that takes in two 2-D arrays of numbers and returns their matrix multiplication result.Let’s write the code for this function −ExampleThe code for this will be −const multiplyMatrices = (a, b) => {    if (!Array.isArray(a) || !Array.isArray(b) || !a.length || !b.length) {       throw new Error('arguments should be in 2-dimensional array format');    }    let x = a.length,    z = a[0].length,    y = b[0].length;    if (b.length !== z) {       // XxZ & ZxY => XxY       throw new Error('number of ... Read More

Alternate casing a string in JavaScript

AmitDiwan
Updated on 15-Oct-2020 09:31:56

1K+ Views

We are required to write a JavaScript function that takes in a string and constructs a new string with all the uppercase characters from the original string converted to lowercase and all the lowercase characters converted to uppercase from the original string.For example: If the string is −const str = 'The Case OF tHis StrinG Will Be FLiPped';OutputThen the output should be −const output = 'tHE cASE of ThIS sTRINg wILL bE flIpPED';ExampleThe code for this will be −const str = 'The Case OF tHis StrinG Will Be FLiPped'; const isUpperCase = char => char.charCodeAt(0) >= 65 && char.charCodeAt(0) char.charCodeAt(0) ... Read More

Prime factor array of a Number in JavaScript

AmitDiwan
Updated on 15-Oct-2020 09:30:04

323 Views

We are required to write a JavaScript function that takes in a number and returns an array of all the prime numbers that exactly divide the input number.For example, if the input number is 105.Then the output should be −const output = [3, 5, 7];ExampleThe code for this will be −const num = 105; const isPrime = (n) => {    for(let i = 2; i {    const res = num % 2 === 0 ? [2] : [];    let start = 3;    while(start

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