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Articles by AmitDiwan
Page 390 of 840
How 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 MoreFinding all peaks and their positions in an array in JavaScript
A peak (local maximum) in an array is an element that is greater than both its neighbors. Finding all peaks and their positions is useful for data analysis, signal processing, and identifying trends. Problem Statement Given an array of integers, we need to find all local maxima (peaks) and return an object containing two arrays: maximas (the peak values) and positions (their indices). Consider this array: const arr = [4, 3, 4, 7, 5, 2, 3, 4, 3, 2, 3, 4]; console.log("Array:", arr); Array: [4, 3, 4, 7, 5, 2, 3, 4, ...
Read MoreProgram to implement Bucket Sort in JavaScript
Bucket Sort is an efficient sorting algorithm that works by distributing elements into multiple buckets based on their values, then sorting each bucket individually. This approach is particularly effective when the input is uniformly distributed across a range. How Bucket Sort Works The algorithm follows these key steps: Find the minimum and maximum values in the array Create a specific number of buckets to hold ranges of values Distribute array elements into appropriate buckets Sort each bucket using a suitable sorting algorithm (like insertion sort) Concatenate all sorted buckets to get the final result ...
Read MoreGet the correct century from 2-digit year date value - JavaScript?
When working with 2-digit year values, you need to determine which century they belong to. A common approach is using a pivot year to decide between 19XX and 20XX centuries. Example Following is the code − const yearRangeValue = 18; const getCorrectCentury = dateValues => { var [date, month, year] = dateValues.split("-"); var originalYear = +year > yearRangeValue ? "19" + year : "20" + year; return new Date(originalYear + "-" + month + "-" + date).toLocaleDateString('en-GB') }; console.log(getCorrectCentury('10-JAN-19')); console.log(getCorrectCentury('10-JAN-17')); console.log(getCorrectCentury('10-JAN-25')); ...
Read MoreHow to unflatten a JavaScript object in a daisy-chain/dot notation into an object with nested objects and arrays?
When working with flattened objects that use dot notation (like "car.make" or "visits.0.date"), you often need to convert them back into nested objects and arrays. This process is called "unflattening" and is useful when working with form data, APIs, or database results. The Problem Suppose we have a flattened object like this: const obj = { "firstName": "John", "lastName": "Green", "car.make": "Honda", "car.model": "Civic", "car.revisions.0.miles": 10150, "car.revisions.0.code": "REV01", ...
Read MoreHow to convert nested array pairs to objects in an array in JavaScript ?
When working with complex data structures, you often need to convert nested array pairs into objects. This is common when processing form data or API responses that use key-value pair arrays. Problem Statement Suppose we have an array of arrays like this: const arr = [ [ ['firstName', 'Joe'], ['lastName', 'Blow'], ['age', 42], ['role', 'clerk'] ], ...
Read MoreRemoving comments from array of string in JavaScript
We are required to write a JavaScript function that takes in array of strings, arr, as the first argument and an array of special characters, starters, as the second argument. The starter array contains characters that can start a comment. Our function should iterate through the array arr and remove all the comments contained in the strings. Problem Example For example, if the input to the function is: const arr = [ 'red, green !blue', 'jasmine, #pink, cyan' ]; const starters = ['!', '#']; Then the output ...
Read MoreHow to merge specific elements inside an array together - JavaScript
When working with arrays containing mixed data types, you might need to merge consecutive numeric elements while keeping certain separators intact. This is common when processing data that represents grouped numbers. Let's say we have the following array: var values = [7, 5, 3, 8, 9, '/', 9, 5, 8, 2, '/', 3, 4, 8]; console.log("Original array:", values); Original array: [7, 5, 3, 8, 9, '/', 9, 5, 8, 2, '/', 3, 4, 8] Using join() and split() Method To merge specific elements while preserving separators, we can use join(), split(), ...
Read MoreGet all methods of any object JavaScript
In JavaScript, you can extract all methods (functions) from any object using Object.getOwnPropertyNames() combined with type filtering. This is useful for debugging, reflection, or dynamically working with object methods. Understanding the Problem Objects contain both properties (data) and methods (functions). To get only the methods, we need to: Get all property names from the object Filter properties where the value type is "function" Return an array of method names Using Object.getOwnPropertyNames() The Object.getOwnPropertyNames() method returns an array of all properties (enumerable and non-enumerable) found directly on the given object. We then filter this ...
Read MoreSort an array of objects by multiple properties in JavaScript
Sorting an array of objects by multiple properties is a common requirement in JavaScript applications. This involves creating custom comparison logic that prioritizes different properties based on specific criteria. Suppose, we have an array of objects like this: const arr = [ { id: 1, score: 1, isCut: false, dnf: false }, { id: 2, score: 2, isCut: false, dnf: false }, { id: 3, score: 3, isCut: false, dnf: false }, { id: 4, score: 4, isCut: false, dnf: false ...
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