We are required to write a JavaScript function that takes in any arbitrary number of arrays and returns an array of elements that are common to all arrays. If there are no common elements, then we should return an empty array.Let’s say the following are our arrays −const arr1 = [2, 6, 7, 1, 7, 8, 4, 3]; const arr2 = [5, ,7, 2, 2, 1, 3]; const arr3 = [1, 56, 345, 6, 54, 2, 68, 85, 3];ExampleFollowing is the code −const arr1 = [2, 6, 7, 1, 7, 8, 4, 3]; const arr2 = [5, ,7, 2, 2, ... Read More

Suppose, we have an array of objects like this −const people = [    {"id":1, "name":"Andrew", "age":30, "gender":"m", "category":"G"},    {"id":2, "name":"Brandon", "age":25, "gender":"m", "category":"G"},    {"id":3, "name":"Christine", "age":20, "gender":"m", "category":"G"},    {"id":4, "name":"Elena", "age":29, "gender":"W", "category":"M"}   ];We are required to write a JavaScript function that takes in one such array and sorts the array in place, according to the age property of each object in increasing order.Therefore, the output should look something like this −const output = [    {"id":3, "name":"Christine", "age":20, "gender":"m", "category":"G"},    {"id":2, "name":"Brandon", "age":25, "gender":"m", "category":"G"},    {"id":4, "name":"Elena", "age":29, "gender":"W", "category":"M"},    {"id":1, ... Read More

We are required to write a JavaScript function that takes in an array, a start index and an end index. The function should reverse the portion of the array between the start index and end index.For example −If the array is −const arr = [2, 6, 5, 8, 3, 5, 2, 6, 7];And the start index and end index are 3, 7 respectively, then the array should be reversed to −const output = [2, 6, 5, 2, 5, 3, 8, 6, 7];ExampleFollowing is the code −const arr = [2, 6, 5, 8, 3, 5, 2, 6, 7]; const start = ... Read More

In Mathematics, the symmetric difference of two sets, say A and B is represented by A △ BAnd it is defined as the set of all those elements which belongs either to A or to B but not to both.For example −const A = [1, 2, 3, 4, 5, 6, 7, 8]; const B = [1, 3, 5, 6, 7, 8, 9];Then the symmetric difference of A and B will be −const diff = [2, 4, 9]ExampleFollowing is the code −const A = [1, 2, 3, 4, 5, 6, 7, 8]; const B = [1, 3, 5, 6, 7, 8, ... Read More

We are required to write a JavaScript function that takes in a nested array of Numbers and returns the sum of all the numbers present in the array.Let’s say the following is our nested array −const arr = [2, 5, 7, [    4, 5, 4, 7, [        5, 7, 5    ], 5 ], 2];ExampleFollowing is the code −const arr = [2, 5, 7, [    4, 5, 4, 7, [       5, 7, 5    ], 5 ], 2]; const calculateSum = (arr, query) => {    let count = 0;    for(let i = 0; i < arr.length; i++){       if(Array.isArray(arr[i])){          count += calculateSum(arr[i], query);          continue;       };       count += arr[i];    };    return count; }; console.log(calculateSum(arr));OutputThis will produce the following output in console −58

We are required to write a JavaScript function that takes in a number, sums its digits and checks whether that sum is a Palindrome number or not. The function should return true if the sum is Palindrome, false otherwise.For example, if the number is 697, Then the sum of its digit will be 22, which indeed, is a Palindrome number. Therefore, our function should return true for 697.ExampleFollowing is the code −const num = 697; const sumDigit = (num, sum = 0) => {    if(num){       return sumDigit(Math.floor(num / 10), sum + (num % 10));    }; ... Read More

We are required to write a JavaScript function that accepts an array of Numbers and a number, say n (n must be less than or equal to the length of array). And our function should replace the kth element from the beginning with the nth element from the end of the array.ExampleFollowing is the code −const arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; const swapNth = (arr, k) => {    const { length: l } = arr;    let temp;    const ind = k-1;    temp = arr[ind];    arr[ind] = arr[l-k];    arr[l-k] = temp; }; swapKth(arr, 4); console.log(arr); swapNth(arr, 8); console.log(arr);OutputThis will produce the following output in console −[    0, 1, 2, 6, 4,    5, 3, 7, 8, 9 ] [    0, 1, 7, 6, 4,    5, 3, 2, 8, 9 ]

Given a string S, consisting of alphabets, numbers and special characters. We need to write a program to split the strings in three different strings S1, S2 and S3, such that −The string S1 will contain all the alphabets present in S, The string S2 will contain all the numbers present in S, andS3 will contain all special characters present in S.The strings S1, S2 and S3 should have characters in the same order as they appear in input.ExampleFollowing is the code −const str = "Th!s String C0nt@1ns d1fferent ch@ract5rs"; const seperateCharacters = str => {    const strArr = ... Read More

Suppose, we have an object like this −const dataset = {    "diamonds":77,    "gold-bars":28,    "exciting-stuff":52,    "oil":51,    "sports-cars":7,    "bitcoins":40 };We are required to write a JavaScript function that takes one such object and returns an array of objects that have keys and their values splitted.Therefore, for the above object, the output should be −const output = [    {"asset":"diamonds", "quantity":77},    {"asset":"gold-bars", "quantity":28},    {"asset":"exciting-stuff", "quantity":52},    {"asset":"oil", "quantity":51},    {"asset":"bitcoins", "quantity":40} ];ExampleFollowing is the code −const dataset = {    "diamonds":77,    "gold-bars":28,    "exciting-stuff":52,    "oil":51,    "sports-cars":7,    "bitcoins":40 }; const splitKeyValue = ... Read More

We are required to write a JavaScript function that takes in a string and returns the character from the string that appears for second most number of times.Let’s say the following is our string −const str = 'This string will be used to calculate frequency';Above, the second most frequent character is “e”.ExampleLet us now see the complete code −const str = 'This string will be used to calculate frequency'; const secondMostFrequent = str => {    const strArr = str.split('');    const map = strArr.reduce((acc, val) => {       if(acc.has(val)){          acc.set(val, acc.get(val) + 1); ... Read More