In the given problem statement we are asked to generate every possible permutation of the array given as input by the in JavaScript going from brute force method to optimized solution . What is an array in JavaScript ? If you are familiar with any other programming language like C, C++, or Java, you must have heard the term 'array.' In programming, an array is a collection of similar data elements under one roof. Now, an important question arises: if arrays are generally the same in all languages, then how does JavaScript make arrays more ... Read More

We are required to write a JavaScript function that takes in an array of string literals as the first argument and a single string character as the second argument.Then our function should find and return the first array entry that starts with the character specified by the second argument.ExampleThe code for this will be −const names = ['Naman', 'Kartik', 'Anmol', 'Rajat', 'Keshav', 'Harsh', 'Suresh', 'Rahul']; const firstIndexOf = (arr = [], char = '') => {    for(let i = 0; i < arr.length; i++){       const el = arr[i];       if(el.substring(0, 1) === char){   ... Read More

We are required to write a JavaScript function that takes in a number as the only argument. The function should then return a random generated number which is always divisible by the number provided by the argument.ExampleThe code for this will be −const num = 21; // function that generates random numbers divisible by n with a default upper limit of 1000000 const specialRandom = (num = 1, limit = 1000000) => {    // getting a random number    const random = Math.random() * limit;    // rounding it off to be divisible by num    const res = ... Read More

We are required to write a JavaScript function on the prototype object of a BinarySearchTree data type that takes in a value and finds whether or not that value is contained in the BST.ExampleThe code for this will be -// class for a single Node for BST class Node {    constructor(value) {       this.value = value;    } } // class for BST // contains function to insert node and search for existing nodes class BinarySearchTree {    constructor() {       this._root = null;    };    insert(value) {       let node = ... Read More

We are required to write a JavaScript function that takes in an array of exactly two numbers specifying a range.The function should then calculate the least common multiple of all the numbers within that range and return the final result.ExampleThe code for this will be −const range = [8, 3]; const gcd = (a, b) => {    return !b ? a : gcd(b, a % b); } const lcm = (a, b) => {    return a * (b / gcd(a,b)); }; const rangeLCM = (arr = []) => {    if(arr[0] > arr[1]) (arr = [arr[1], arr[0]]);    for(let x = result = arr[0]; x

Let's say we have a variable “users” that contains the following string of text where each user is separated by a semicolon and each attribute of each users is separated by a comma −const users = 'Bob, 1234, Bob@example.com;Mark, 5678, Mark@example.com';We are required to write a JavaScript function that takes in one such string and splits this into a multidimensional array that looks like this −const arr = [    ['Bob', 1234, 'Bob@example.com'],    ['Mark', 5678, 'Mark@example.com'] ];ExampleThe code for this will be −const users = 'Bob, 1234, Bob@example.com;Mark, 5678, Mark@example.com'; const splitByPunctuations = (str = '') => {   ... Read More

This problem takes its name by arguably the most important event in the life of the ancient historian Josephus − according to his tale, he and his 40 soldiers were trapped in a cave by the Romans during a siege.Refusing to surrender to the enemy, they instead opted for mass suicide, with a twist − they formed a circle and proceeded to kill one man every three, until one last man was left (and that it was supposed to kill himself to end the act).Josephus and another man were the last two and, as we now know every detail of ... Read More

Suppose we have a number, const num = 76;However, If we round off this number to nearest 10 place, the result will be 80If we round off this number to nearest 100 place, the result will be 100If we round off this number to nearest 1000 place, the result will be 0We are required to write a JavaScript function that takes in a number to be rounded as the first argument and the rounding off factor as the second argument.The function should return the result after rounding off the number.ExampleThe code for this will be −const num = 76; const ... Read More

Suppose we have an array of objects that contains the data about some students and their marks like this −const arr = [    { subject: 'Maths', marks: '40', noOfStudents: '5' },    { subject: 'Science', marks: '50', noOfStudents: '16' },    { subject: 'History', marks: '35', noOfStudents: '23' },    { subject: 'Science', marks: '65', noOfStudents: '2' },    { subject: 'Maths', marks: '30', noOfStudents: '12' },    { subject: 'History', marks: '55', noOfStudents: '20' }, ];We are required to write a JavaScript function that takes in one such array.The function should eliminate the redundant entries on the basis ... Read More

Suppose we have a JSON object like this −const obj = {    "LAPTOP": [{       "productId": "123"    }],    "DESKTOP": [{       "productId": "456"    }],    "MOUSE": [{       "productId": "789"    }, {       "productId": "012"    }],    "KEY-BOARD": [{       "productId": "345"    }] };We are required to write a JavaScript function that takes in one such object as the first argument, and a key value pair as the second argument.The key value pair is basically nothing but an object like this −const pair ... Read More