Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Front End Technology Articles
Page 229 of 652
How to store two arrays as a keyvalue pair in one object in JavaScript?
Suppose, we have two arrays of literals of same length like these − const arr1 = ['firstName', 'lastName', 'age', 'address', 'isEmployed']; const arr2 = ['Rahul', 'Sharma', 23, 'Tilak Nagar', false]; We are required to write a JavaScript function that takes in two such arrays. The function should construct an object mapping the elements of the second array to the corresponding elements of the first array. Method 1: Using Array.reduce() We will use the Array.prototype.reduce() method to iterate over the arrays, building the object. const arr1 = ['firstName', 'lastName', 'age', 'address', 'isEmployed']; ...
Read MoreFinding the longest "uncommon" sequence in JavaScript
We are required to write a JavaScript function that takes in an array of strings. The function should find the longest uncommon subsequence among the strings of the array. By longest uncommon subsequence we mean the longest subsequence of one of these strings and this subsequence should not be any subsequence of the other strings. Our function should return the length of this longest uncommon subsequence. For example: If the input array is − const arr = ["aba", "cdc", "eae"]; Then the output should be 3. Understanding the Problem The key ...
Read MoreFinding product of an array using recursion in JavaScript
We are required to write a JavaScript function that takes in an array of numbers. Our function should do the following two things: Make use of a recursive approach. Calculate the product of all the elements in the array. And finally, it should return the product. For example, if the input array is: const arr = [1, 3, 6, 0.2, 2, 5]; Then the output should be: 36 How Recursion Works Recursion breaks down the problem into smaller subproblems. For ...
Read MoreFind what numbers were pressed to get the word (opposite of phone number digit problem) in JavaScript
The mapping of the numerals to alphabets in the old keypad type phones used to be like this: const mapping = { 1: [], 2: ['a', 'b', 'c'], 3: ['d', 'e', 'f'], 4: ['g', 'h', 'i'], 5: ['j', 'k', 'l'], 6: ['m', 'n', 'o'], 7: ['p', 'q', 'r', 's'], 8: ['t', 'u', 'v'], 9: ['w', 'x', 'y', 'z'] }; console.log(mapping); { '1': [], '2': [ 'a', 'b', 'c' ], '3': ...
Read MoreAre the strings anagrams in JavaScript
Two strings are said to be anagrams of each other if by rearranging, rephrasing or shuffling the letters of one string we can form the other string. Both strings must contain exactly the same characters with the same frequency. For example, 'something' and 'emosghtin' are anagrams of each other because they contain the same letters with the same count. We need to write a JavaScript function that takes two strings and returns true if they are anagrams of each other, false otherwise. Method 1: Character Frequency Count This approach counts the frequency of each character in ...
Read MoreSubset with maximum sum in JavaScript
In JavaScript, finding the subset of non-adjacent elements with maximum sum is a classic dynamic programming problem. We need to decide whether to include each element or skip it, ensuring no two adjacent elements are selected. The key insight is that for each element, we have two choices: include it (and skip the previous element) or exclude it (and take the maximum sum up to the previous element). Problem Statement Given an array of integers, find the subset of non-adjacent elements that produces the maximum sum. Adjacent elements cannot be selected together. For example, with the ...
Read MoreCheck if the string is a combination of strings in an array using JavaScript
We are required to write a JavaScript function that takes in an array of strings as the first argument and a string as the second argument. The function should check whether the string specified by second argument can be formed by combining the strings of the array in any possible way. For example − If the input array is − const arr = ["for", "car", "keys", "forth"]; And the string is − const str = "forthcarkeys"; Then the output should be true, because the string is a combination of elements ...
Read MoreHow to build a string with no repeating character n separate list of characters? in JavaScript
When working with multiple arrays of characters, we often need to create combinations where each string contains exactly one character from each array with no duplicate characters. This is useful for generating unique combinations while avoiding repeated letters that might exist across different arrays. Problem Overview Given multiple arrays of characters, we need to build all possible strings that: Contains exactly one letter from each array ...
Read MoreSplit number into 4 random numbers in JavaScript
We need to write a JavaScript function that takes a total number and a maximum value, then generates four random numbers that sum to the total while ensuring none exceeds the maximum. The function should generate four random numbers where: All four numbers sum to the given total No number exceeds the specified maximum Repetition of numbers is allowed For example, if the total is 10 and maximum is 4, a valid output could be [3, 2, 3, 2]. Algorithm Overview The algorithm works by: Generating random values between 0 and 1 Scaling ...
Read MoreHow to check if an array contains integer values in JavaScript ?
In JavaScript, checking if an array contains integer values requires understanding the difference between numbers and strings that look like numbers. This article explores different approaches to detect actual integer values in arrays. The Problem with String Numbers Arrays often contain string representations of numbers like "123" instead of actual numbers. We need to distinguish between these types. const mixedArray = ["123", 45, "hello", 67.5, "89"]; console.log(typeof "123"); // "string" console.log(typeof 45); // "number" string number Method 1: Using typeof and Number.isInteger() The most ...
Read More