Front End Technology Articles - Page 393 of 860

We are required to write a JavaScript function that takes in an array of numbers. The function should sort the array with using the Array.prototype.sort() method. We are required to use the Array.prototype.reduce() method to sort the array.Let’s say the following is our array −const arr = [4, 56, 5, 3, 34, 37, 89, 57, 98];ExampleFollowing is the code −// we will sort this array but // without using the array sort function // without using any kind of conventional loops // using the ES6 function reduce() const arr = [4, 56, 5, 3, 34, 37, 89, 57, 98]; const ... Read More

We are required to write a JavaScript function that takes in a number and returns a new number in which all the digits of the original number are squared and concatenatedFor example: If the number is −9119Then the output should be −811181because 9^2 is 81 and 1^2 is 1.ExampleFollowing is the code −const num = 9119; const squared = num => {    const numStr = String(num);    let res = '';    for(let i = 0; i < numStr.length; i++){       const square = Math.pow(+numStr[i], 2);       res += square;    };    return res; }; console.log(squared(num));OutputThis will produce the following output in console −811181

We are required to write a JavaScript function takes in an array of numbers. The function should bring all the 3-digit integers to the front of the array.Let’s say the following is our array of numbers −const numList = [1, 324,34, 3434, 304, 2929, 23, 444];ExampleFollowing is the code −const numList = [1, 324,34, 3434, 304, 2929, 23, 444]; const isThreeDigit = num => num > 99 && num < 1000; const bringToFront = arr => {    for(let i = 0; i < arr.length; i++){       if(!isThreeDigit(arr[i])){          continue;       };       arr.unshift(arr.splice(i, 1)[0]);    }; }; bringToFront(numList); console.log(numList);OutputThis will produce the following output in console −[   444, 304,  324,     1,  34, 3434,  2929,  23 ]

In the given problem statement we are presented with a number and we have to sum up the given number until it becomes one digit and implement the code in Javascript for getting the required sum. Understanding the Problem In the given program we will have a number and our task is to repeatedly sum its digits until the outcome of the number becomes a single digit. For example suppose we have a number like 874563 and we need to add all of its digits (8 + 7 + 4 + 5 + 6 + 3 = ... Read More

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