We are required to write a JavaScript function that takes in two objects (possibly nested) and returns a new object with key value pair for the keys that were present in the first object but not in the secondLet's write the code for this function −Exampleconst obj1 = {    "firstName": "Raghav",    "lastName": "Raj",    "age": 43,    "address": "G-12 Kalkaji",    "email": "raghavraj1299@yahoo.com",    "salary": 90000 }; const obj2 = {    "lastName": "Raj",    "address": "G-12 Kalkaji",    "email": "raghavraj1299@yahoo.com",    "salary": 90000 }; const objectDifference = (first, second) => {    return Object.keys(first).reduce((acc, val) => { ... Read More

We are required to write a JavaScript function that takes in a string with repetitive characters and returns a new string in which all the same characters are exactly n characters away from each other. And the number should be smaller than the length of the array.For example −If the input string is: "accessories" And the number n is 3 Then, The return value should be: "secrsecisao"Note − There may be some other permutation to achieve the required output, the order is not important, we should stick to the logic and as long as we fulfil it our output is ... Read More

We have an array of arrays that contains the marks scored by some students in some subjects −const arr = [    ['Math', 'John', 100],    ['Math', 'Jake', 89],    ['Math', 'Amy', 93],    ['Science', 'Jake', 89],    ['Science', 'John', 89],    ['Science', 'Amy', 83],    ['English', 'John', 82],    ['English', 'Amy', 81],    ['English', 'Jake', 72] ];We are required to write a function that takes in this array and retuns an array of object, with one object for each subject and the details about the top scorer of that subject.Our output should look like −[    { "Subject": "Math", ... Read More

We are required to write a JavaScript function that takes in a string and a number n as two arguments (the number should be such that it exactly divides the length of string). And we have to return an array of n strings of equal length.For example −If the string is "helloo" and the number is 3 Our output should be: ["ho", "eo", "ll"]Here, each substring exactly contains (length of array/n) characters. And each substring is formed by taking corresponding first and last letters of the string alternativelyLet's write the code for this function −Exampleconst str = 'helloo'; const splitEqual ... Read More

We are required to write a JavaScript function that takes in an array of Numbers with some positive and negative values. We are required to determine whether there exists a subarray in the original array whose net sum is 0 or not.Our function should return a boolean on this basis.ApproachThe approach here is simple. We iterate over the array using a for loop, calculate the cumulative sum up to that particular element. And if any point the cumulative becomes 0 or attains a value it has previously attained, then there exists a subarray with sum 0. Otherwise there exists no ... Read More

We are required to write a JavaScript String function that overwrite the default toLowerCase() and should have the same functionality as the default function.Let's write the code for this function −Exampleconst str = 'Some UpPerCAsE LeTTeRs!!!'; const toLowerCase = function(){    let str = '';    for(let i = 0; i < this.length; i++){       const ascii = this[i].charCodeAt();       if(ascii >= 65 && ascii

We have an array of Numbers that contains 0, 1 and some other numbers. We are required to write a JavaScript function that takes in this array and brings all 1s to the start and 0s to the endLet's write the code for this function −Exampleconst arr = [3, 2, 1, 8, 9, 0, 1, 9, 0, 2, 1, 0, 2, 0, 1, 0, 1, 1, 4, 0, 3]; const segregate = arr => {    const copy = arr.slice();    for(let i = 0; i < copy.length; i++){       if(copy[i] === 0){          copy.push(copy.splice(i, 1)[0]);       }else if(copy[i] === 1){          copy.unshift(copy.splice(i, 1)[0]);       };       continue;    };    return copy; }; console.log(segregate(arr));OutputThe output in the console will be −[    1, 1, 1, 3, 2, 8, 9,    1, 9, 2, 2, 1, 1, 4,    3, 0, 0, 0, 0, 0, 0 ]

In Mathematics, a Mersenne prime is a number that can be written in the form M(n) = 2^n − 1 for some integer n and is actually a prime number.For example − The first four Mersenne primes are 3, 7, 31, and 127We are required to write a JavaScript function that takes in a number and checks whether it is a Mersenne prime or not. Let’s write the code for this functionExampleconst isPrime = num => {    let i = 2;    while(i {    if(!isPrime(num)){       return false;    };    let i = 0, ... Read More

We are required to write a JavaScript function that takes in two strings and checks whether first string starts with second or notFor example −If the two strings are: “Disaster management report” “Disas” Then our function should return trueLet's write the code for this function −Exampleconst first = 'The game is on'; const second = 'The'; const startsWith = (first, second) => {    const { length } = second;    const { length: l } = first;    const sub = first.substr(0, length);    return sub === second; }; console.log(startsWith(first, second));OutputThe output in the console will be −true

An element in an array of Numbers is a leader if it is greater than all the elements on its right side. We are required to write a JavaScript function that takes in an array of Numbers and returns a subarray of all the elements that are fulfil the criteria of being a leader element.For example −If the input array is: [23, 55, 2, 56, 3, 6, 7, 1] Then the output should be: [56, 7, 1]Let's write the code for this function −Exampleconst arr = [23, 55, 2, 56, 3, 6, 7, 1]; const leaderArray = arr => { ... Read More