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The find() method searches through an array and returns the first element that matches a specified condition. It's perfect for locating specific records in arrays of objects. Syntax array.find(callback(element, index, array)) Parameters callback - Function to test each element element - Current element being processed index (optional) - Index of current element array (optional) - The array being searched Return Value Returns the first element that satisfies the condition, or undefined if no element is found. Example: Finding a Student Record var students = [ ... Read More
In JavaScript, iterating over JSON arrays is a common task when working with data from APIs or configuration files. A JSON array is an ordered list of values that can contain strings, numbers, booleans, objects, or other arrays. This article demonstrates various methods to iterate through JSON arrays in JavaScript, from traditional loops to modern ES6+ approaches. Understanding JSON Arrays JSON arrays are ordered collections of values enclosed in square brackets. Each element is separated by commas and can be accessed using numeric indices. Syntax [ { ... Read More
In JavaScript, you often need to count how many times specific strings appear in an array of sentences. This article demonstrates how to find the exact individual count of each string from a given array within multiple sentences using regular expressions and word boundaries. Understanding the Problem Given an array of strings and an array of sentences, we need to count how many times each string appears across all sentences. The key requirement is to match complete words only, not partial matches within other words. ... Read More
We are required to write a JavaScript function that takes in an array of numbers, arr, as the first argument and a single number, num, as the second argument. The function should then find two such numbers whose sum is greatest in the array but just less than the number num. If there exists no two such numbers whose sum is less than num, our function should return -1. Problem Statement Given an array of numbers and a target value, find the maximum sum of any two elements that is still less than the target. For ... Read More
We are required to write a JavaScript function that takes in a number and returns the count of its divisors. Problem Statement Input: const num = 30; Expected Output: const output = 8; Because the divisors of 30 are: 1, 2, 3, 5, 6, 10, 15, 30 Method 1: Simple Iteration Approach The straightforward approach is to iterate through all numbers from 1 to the given number and count those that divide evenly. const countDivisorsSimple = (num) => { ... Read More
The crypto.pbkdf2() method in Node.js implements the Password-Based Key Derivation Function 2 (PBKDF2) algorithm. It derives a cryptographic key from a password using a salt and multiple iterations to enhance security against brute-force attacks. Syntax crypto.pbkdf2(password, salt, iterations, keylen, digest, callback) Parameters The parameters are described as follows: password – The password string used for key derivation. Accepts string, Buffer, TypedArray, or DataView. ... Read More
In this article, we are going to learn about how to disable uniform scaling in canvas using FabricJS. In FabricJS, an object gets transformed proportionally when dragged from the corners. However, we can disable this behavior by using the uniformScaling property. Syntax new fabric.Canvas(element: HTMLElement|String, { uniformScaling: Boolean }: Object) Parameters element − This parameter is the element itself which can be derived using document.getElementById() or the id of the element itself. The FabricJS canvas will be initialized on this element. options (optional) ... Read More
In this tutorial, we are going to learn how to set the size of the controlling corners of a Rectangle using FabricJS. The controlling corners of an object allow us to scale, stretch or change its position. We can customize our controlling corners in many ways such as adding a specific colour to it, changing its size etc. We can change the size by using the cornerSize property. Syntax new fabric.Rect({ cornerSize: Number }: Object) Parameters Options (optional) − This parameter is an Object which provides additional customizations to ... Read More
Adding class names to different list items (li elements) is a common task in JavaScript DOM manipulation. This can be achieved using various methods like forEach() with classList.add(), CSS selectors, or DOM traversal properties. Let's explore different approaches to add class names to list items using pure JavaScript. Method 1: Using forEach() with classList.add() The forEach() method executes a function for each array element, while classList.add() adds one or more CSS classes to an element. Syntax array.forEach(function(currentValue, index, arr), thisValue) element.classList.add('className') Example ... Read More
By using JavaScript's native array methods and functions, we can easily create custom sorting algorithms that will work for any type of object. In this article, we will discuss how to use these techniques in order to sort an object's key-value pairs by value. A key-value pair in JavaScript such as maps, dictionaries stores one value (the "key") associated with another value (the "value"). It can be used to store and access data quickly, as each element has its own unique identifier. For sorting key value pair object based on the value, we use sort() method in JavaScript. ... Read More