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Articles by AmitDiwan
Page 328 of 840
Finding value of a sequence for numbers in JavaScript
In JavaScript, we can calculate the value of mathematical sequences using loops and built-in Math functions. This article demonstrates how to implement a specific sequence formula that involves alternating signs, powers, and fractions. Problem Consider the following sequence sum: $$seq(n, \:p)=\displaystyle\sum\limits_{k=0}^{n}(-1)^{k}\times\:p\:\times 4^{n-k}\:\times\frac{2n-k}{k}$$ We need to write a JavaScript function that takes numbers n and p and returns the value of seq(n, p). The sequence includes alternating signs, exponential terms, and fractional components. Understanding the Formula The sequence contains several key components: (-1)^k - Creates alternating positive and negative terms p - A ...
Read MoreCount and return the number of characters of str1 that makes appearances in str2 using JavaScript
We need to write a JavaScript function that takes two strings as parameters and counts how many characters from the first string appear in the second string, including duplicate occurrences. Problem Statement Given two strings str1 and str2, count how many characters from str1 also appear in str2. If a character appears multiple times in str2, count each occurrence separately. Example: str1 = 'Kk' contains characters 'K' and 'k' str2 = 'klKKkKsl' contains: k(1), l(1), K(2), K(3), k(4), K(5), s(6), l(7) Characters from str1 found in str2: k, K, K, k, K = 5 matches ...
Read MoreReturn a map representing the frequency of each data type in an array in JavaScript
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]; Understanding the Problem We need to count how many times each JavaScript data type appears in the array. JavaScript's typeof operator will help us identify the data type of each ...
Read MoreAlgorithm to add binary arrays in JavaScript
In this problem statement, our target is to add two binary arrays with the help of JavaScript. So we will break down the problem step by step to ensure understanding. What is a Binary Array? A binary array is an array that represents a binary number. In a binary number system we have only two possible digits, 0 and 1. The binary array will have elements which can only be 0s and 1s. Every item in the array represents a bit of the binary number. For example, we have a binary array [1, 0, 1, 0]. This ...
Read MoreConverting to hex and summing the numeral part in JavaScript
We are required to write a JavaScript function that takes in a string, converts every character to its hex ASCII value, then sums only the numeric digits (0-9) from the hex representation, ignoring letters (a-f). Problem Given a string, we need to: Convert each character to its ASCII code Convert ASCII codes to hexadecimal Extract only numeric digits from the hex strings Sum all the numeric digits Example Let's see how this works with a complete example: const str = "Hello, World!"; const toHexAndSum = (str = '') => { ...
Read MoreCreate palindrome by changing each character to neighboring character in JavaScript
We need to write a JavaScript function that determines if we can create a palindrome by changing each character to its neighboring character in the alphabet. Each character can only move one position forward or backward (except 'a' can only go to 'b' and 'z' can only go to 'y'). Problem Requirements The function must handle these constraints: Each character MUST be changed either to the one before or the one after in the alphabet "a" can only be changed to "b" and "z" to "y" Return true if at ...
Read MoreChecking for particular types of matrix in JavaScript
We need to write a JavaScript function that checks if every diagonal from top-left to bottom-right in a 2D matrix has identical elements. This is useful for pattern recognition and matrix analysis tasks. Problem Statement Given a 2D array, our function should verify that all elements in each diagonal (running from top-left to bottom-right) are the same. If this condition is met for all diagonals, return true, otherwise false. For example, consider this matrix: const arr = [ [6, 7, 8, 9], [2, 6, 7, 8], ...
Read MoreHow to remove falsy values from an array in JavaScript?
In JavaScript, falsy values are values that evaluate to false in a boolean context. These include false, 0, "", null, undefined, and NaN. Removing falsy values from an array is a common operation that can be accomplished using several methods. What are Falsy Values? JavaScript has six falsy values that evaluate to false when used in boolean contexts: const falsyValues = [false, 0, "", null, undefined, NaN]; console.log("Falsy values:"); falsyValues.forEach(value => { console.log(`${value} is falsy:`, !value); }); Falsy values: false is falsy: true 0 is falsy: true is ...
Read MorePairing an array from extreme ends in JavaScript
We are required to write a JavaScript function that takes in an array of Number / String literals and returns another array of arrays. With each subarray containing exactly two elements, the nth element from start and nth from last. For example: If the array is − const arr = [1, 2, 3, 4, 5, 6]; Then the output should be − [[1, 6], [2, 5], [3, 4]] Example The code for this will be − const arr = [1, 2, 3, 4, 5, 6]; const edgePairs ...
Read MoreChecking for a Doubleton Number in JavaScript
A "doubleton number" is a natural number that contains exactly two distinct digits. For example, 23, 35, 100, and 12121 are doubleton numbers because they each use only two different digits. Numbers like 123 (three digits) and 9980 (three digits: 9, 8, 0) are not doubleton numbers. Problem Statement We need to write a JavaScript function that takes a number and returns true if it's a doubleton number, false otherwise. Solution The approach is to convert the number to a string, track unique digits using an object, and check if exactly two distinct digits exist. ...
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