In this article, the given task is to get the factorial of a number in JavaScript. What is the factorial of a number? The multiplication of all positive integers smaller than or equal to n gives the factorial of a non-negative integer. For example, assume the non-negative integer is 4 and the factorial of 4 will be 4*3*2*1 which is equal to 24. The symbol of factorial is represented by "!". so it will be (4!). The value of 0! Will be 1 as 0 is not a positive integer. The mathematical formula of factorial ("n!") This is ... Read More

Given there is an array with some empty indices and need to remove those empty indices from array. Let’s look into the input output scenarios – Consider there is an array with some empty indices. Now we need to exclude them and return the elements which are having only truthy values. Array = [22, 45, , 56, 71, , 10]; Output = [22, 45, 56, 71, 10] As we can see in the output, the indices which are empty in the array got removed. We can achieve the above task by using several methods, let’s look into the ... Read More

Suppose, we have two arrays like these −const arr1 = ['d', 'a', 'b', 'c'] ; const arr2 = [{a:1}, {c:3}, {d:4}, {b:2}];We are required to write a JavaScript function that accepts these two arrays. The function should sort the second array according to the elements of the first array.We have to sort the keys of the second array according to the elements of the first array.Therefore, the output should look like −const output = [{d:4}, {a:1}, {b:2}, {c:3}];Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr1 = ['d', 'a', 'b', 'c'] ; const ... Read More

Suppose, we have two arrays like these −const arr1 = [1, 2, 3, 4, 5, 6]; const arr2 = [9, 8, 7, 5, 8, 3];We are required to write a JavaScript function that takes in such two arrays and returns an array of absolute difference between the corresponding elements of the array.So, for these arrays, the output should look like −const output = [8, 6, 4, 1, 3, 3];We will use a for loop and keep pushing the absolute difference iteratively into a new array and finally return the array.Therefore, let’s write the code for this function −ExampleThe code for ... Read More

We are required to write a JavaScript function that takes in a number, say n, and an array of two numbers that represents a range. The function should return an array of n random elements all lying between the range provided by the second argument.Therefore, let’s write the code for this function −ExampleThe code for this will be −const num = 10; const range = [5, 15]; const randomBetween = (a, b) => {    return ((Math.random() * (b - a)) + a).toFixed(2); }; const randomBetweenRange = (num, range) => {    const res = [];    for(let i = ... Read More

Suppose, we have a string with digits like this −const str = '11222233344444445666';We are required to write a JavaScript function that takes in this string and returns an object that represents the count of each number in the string.So, for this string, the output should be −const output = {    "1": 2,    "2": 4,    "3": 3,    "4": 7,    "5": 1,    "6": 3 };Therefore, let’s write the code for this function −ExampleThe code for this will be −const str = '11222233344444445666'; const mapString = str => {    const map = {};    for(let i ... Read More

We are required to write a JavaScript function that takes in an array of numbers that may contain some duplicate numbers. Our function should return the sum of all the unique elements (elements that only appear once in the array) present in the array.For exampleIf the input array is −const arr = [2, 5, 5, 3, 2, 7, 4, 9, 9, 11];Then the output should be 25.We will simply use a for loop, iterate the array and return the sum of unique elements.ExampleThe code for this will be −const arr = [2, 5, 5, 3, 2, 7, 4, 9, 9, ... Read More

Suppose, we have an array of objects like this −const arr = [{a: 2, b: 5, c: 6}, {a:3, b: 4, d:1}, {a: 1, d: 2}];Each object is bound to have unique in itself (for it to be a valid object), but two different objects can have the common keys (for the purpose of this question).We are required to write a JavaScript function that takes in one such array and returns an object with all the unique keys present in the array and their values cumulative sum as the value.So, the resultant object should look like −const output = {a: ... Read More

We are required to write a JavaScript function that takes in an array of String / Number literals and returns a subarray of all the elements that were palindrome in the original array.For exampleIf the input array is −const arr = ['carecar', 1344, 12321, 'did', 'cannot'];Then the output should be −const output = [12321, 'did'];We will create a helper function that takes in a number or a string and checks if its a boolean or not.Then we will loop over the array, filter the palindrome elements and return the filtered array.Therefore, let’s write the code for this function −ExampleThe code ... Read More

Suppose, we have an object like this −const products = {    "Pineapple":38,    "Apple":110,    "Pear":109 };All the keys are unique in themselves and all the values are unique in themselves.We are required to write a function that accepts a value and returns its key. Let' say we have created a function findKey().For example, findKey(110) should return "Apple".We will approach this problem by first reverse mapping the values to keys and then simply using object notations to find their values.Therefore, let’s write the code for this function −ExampleThe code for this will be −const products = {    "Pineapple":38, ... Read More