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The idea here is to take two strings as input and return true if one string is a substring of the other, otherwise return false. For example: isSubstr('hello', 'hello world') // true isSubstr('can I use', 'I us') // true isSubstr('can', 'no we are') // false In the function, we check which string is longer and then verify if the shorter string exists as a substring within the longer one. Syntax const isSubstr = (first, second) => { if (first.length > second.length) { ... Read More
To filter JSON data with multiple objects, you can use the filter() method along with comparison operators. This allows you to extract specific objects based on criteria. Syntax array.filter(callback(element, index, array)) Example: Filter by Single Property const jsonObject = [ { studentId: 101, studentName: "David" }, { studentId: 102, ... Read More
We are required to write a JavaScript function that takes in a number and determines if the provided number is a semiprime or not. What is a Semiprime? A semiprime number is a special type of composite number that is the product of exactly two prime numbers (not necessarily distinct). For example: 6 = 2 × 3 (product of two distinct primes) 15 = 3 × 5 (product of two distinct primes) 10 = 2 × 5 (product of two distinct primes) 4 = 2 × 2 (square of a prime) 9 = 3 × 3 ... Read More
An array is the most popular and adaptable data structure you might employ in your regular programming. Converting an array into a JavaScript String can be done using several predefined methods and techniques. Using the toString() Method Using the join() Method Using JSON.stringify() Method Using Type Coercion Using the toString() Method The toString() method is a built-in JavaScript function that converts array elements into a comma-separated string. It's the simplest way to convert an array to string format. ... Read More
In this tutorial, we will learn to assign a function to a variable in JavaScript. Functions are reusable code blocks that can be stored in variables as expressions. There are two main ways to achieve this: using anonymous functions and arrow functions. Most JavaScript programmers are familiar with named functions, which follow this syntax: function function_name() { // function body } However, when we want to assign a function to a variable as an expression, we have two different approaches: Creating Anonymous Functions ... Read More
The oninput event occurs whenever the value of an input element changes. Unlike onchange, which fires only when the element loses focus, oninput triggers immediately as the user types, making it ideal for real-time validation and live search functionality. Syntax // HTML attribute // JavaScript property element.oninput = function() { /* code */ }; // Event listener element.addEventListener('input', function() { /* code */ }); Basic Example oninput Example Type something below: ... Read More
To set an image as the marker in list items, use the listStyleImage property in JavaScript. This property allows you to replace default list markers (bullets or numbers) with custom images. Syntax element.style.listStyleImage = "url('image-path')"; Example The following example demonstrates how to set a custom image as the list-item marker: First Item Second Item Third Item ... Read More
WebSockets can handle binary data transfer using base64 encoding/decoding. Modern browsers provide built-in methods window.btoa() for encoding and window.atob() for decoding base64 data. Base64 Encoding for Binary Transfer When transferring binary data through WebSockets, encode it as base64 on the client side before sending: // Create WebSocket connection const socket = new WebSocket('ws://localhost:8080'); // Convert ... Read More
In JavaScript, there are multiple ways to remove elements from dictionary-like structures. This depends on whether you're working with plain objects, custom dictionary classes, or ES6 Maps. Using delete Operator with Objects For plain JavaScript objects acting as dictionaries, use the delete operator: const dict = { key1: "value1", key2: "value2", key3: "value3" }; console.log("Before deletion:", dict); delete dict.key2; console.log("After deletion:", dict); console.log("key2 exists:", "key2" in dict); Before deletion: { key1: 'value1', key2: 'value2', key3: 'value3' } After ... Read More
JavaScript animations are created by repeatedly changing CSS properties over time using functions like setInterval() or requestAnimationFrame(). This allows you to create smooth visual effects directly in the browser. Basic Animation Principles JavaScript animations work by: Selecting the element to animate Using a timer function to repeatedly update CSS properties Incrementing position, size, or other properties each frame Stopping the animation when the target is reached Example: Moving and Morphing Animation ... Read More