The primorial of a number n is equal to the product of first n prime numbers.For example, if n = 4Then, the output primorial(n) is, 2*3*5*7 = 210We are required to write a JavaScript function that takes in a number and returns its primordial.ExampleFollowing is the code −const num = 4; const isPrime = n => {    if (n===1){       return false;    }else if(n === 2){       return true;    }else{       for(let x = 2; x < n; x++){          if(n % x === 0){       ... Read More

We are required to write a JavaScript function that takes in an array that contains elements of different data types and the function should return a map representing the frequency of each data type.Let’s say the following is our array −const arr = [23, 'df', undefined, null, 12, {    name: 'Rajesh' }, [2, 4, 7], 'dfd', null, Symbol('*'), 8];ExampleFollowing is the code −const arr = [23, 'df', undefined, null, 12, {    name: 'Rajesh'},    [2, 4, 7], 'dfd', null, Symbol('*'), 8]; const countDataTypes = arr => {    return arr.reduce((acc, val) => {       const dataType ... Read More

We are required to write a JavaScript function that takes in two arrays of numbers.And the function should return true if the two arrays upon combining and shuffling can form a consecutive sequence, false otherwise.For example − If the arrays are −const arr1 = [4, 6, 2, 9, 3]; const arr2 = [1, 5, 8, 7];Then the output should be true.ExampleFollowing is the code −const arr2 = [1, 5, 8, 7]; const canFormSequence = (arr1, arr2) => {    const combined = [...arr1, ...arr2];    if(combined.length < 2){       return true;    };    combined.sort((a, b) => a-b); ... Read More

We are required to write a JavaScript function that takes in a string sentence as first and the only argument. The function should return the length of the second smallest word from the string.For example: If the string is −const str = 'This is a sample string';Then the output should be 2.ExampleFollowing is the code −const str = 'This is a sample string'; const secondSmallest = str => {    const strArr = str.split(' ');    if(strArr.length < 2){       return false;    }    for(let i = 0; i < strArr.length; i++){       strArr[i] = ... Read More

Suppose we are given a number 124 and are required to write a function that takes this number as input and returns its expanded form as a string.The expanded form of 124 is −'100+20+4'ExampleFollowing is the code −const num = 125; const expandedForm = num => {    const numStr = String(num);    let res = '';    for(let i = 0; i < numStr.length; i++){       const placeValue = +(numStr[i]) * Math.pow(10, (numStr.length - 1 - i));       if(numStr.length - i > 1){          res += `${placeValue}+`       }else{          res += placeValue;       };    };    return res; }; console.log(expandedForm(num));OutputFollowing is the output in the console −100+20+5

We are required to write a JavaScript function that takes in a string as the first argument, a number, say n, as the second argument and a character, say c, as the third argument. The function should replace the nth appearance of any character with the character provided as the third argument and return the new string.ExampleFollowing is the code −const str = 'This is a sample string'; const num = 2; const char = '*'; const replaceNthAppearance = (str, num, char) => {    const creds = str.split('').reduce((acc, val, ind, arr) => {       let { res, ... Read More

We are required to write a JavaScript function that takes in an array of numbers and returns a subarray that contains all the element from the original array that are larger than all the elements on their right.ExampleFollowing is the code −const arr = [12, 45, 6, 4, 23, 23, 21, 1]; const largerThanRight = (arr = []) => {    const creds = arr.reduceRight((acc, val) => {       let { largest, res } = acc;       if(val > largest){          res.push(val);          largest = val;       };       return { largest, res };    }, {       largest: -Infinity,       res: []    });    return creds.res; }; console.log(largerThanRight(arr));OutputFollowing is the output in the console −[ 1, 21, 23, 45 ]

A string can be considered as a valid hex code if it contains no characters other than the 0-9 and a-f alphabetsFor example −'3423ad' is a valid hex code '4234es' is an invalid hex codeWe are required to write a JavaScript function that takes in a string and checks whether its a valid hex code or not.ExampleFollowing is the code −const str1 = '4234es'; const str2 = '3423ad'; const isHexValid = str => {    const legend = '0123456789abcdef';    for(let i = 0; i < str.length; i++){       if(legend.includes(str[i])){          continue;       ... Read More

We are required to write a JavaScript function that takes in an positive integer and returns its additive persistenceThe additive persistence of an integer, say n, is the number of times we have to replace the number with the sum of its digits until the number becomes a single digit integer.For example −If the number is −1679583Then, 1 + 6 + 7 + 9 + 5 + 8 + 3 = 39   // 1 Pass 3 + 9 = 12                   // 2 Pass 1 + 2 = 3     ... Read More

We are required to write a JavaScript function that takes in an array of numbers and checks if the elements of the array can be rearranged to form a sequence of numbers or not.For example −If the array is −const arr = [3, 1, 4, 2, 5];Then the output should be −trueExampleFollowing is the code −const arr = [3, 1, 4, 2, 5]; const canBeConsecutive = (arr = []) => {    if(!arr.length){       return false;    };    const copy = arr.slice();    copy.sort((a, b) => a - b);    for(let i = copy[0], j = 0; ... Read More