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
Web Development Articles
Page 435 of 801
Get value from div with JavaScript resulting undefined?
When trying to get the value from a div element using JavaScript, you might encounter undefined results if you use incorrect properties. The key is understanding the difference between innerHTML, textContent, and value. The Problem The most common mistake is using .value on div elements. The value property only works for form inputs like , , and . For div elements, use innerHTML or textContent. Using innerHTML innerHTML gets the HTML content inside the element, including any HTML tags: Get Div Value ...
Read MoreHow to override derived properties in JavaScript?
In JavaScript, when an object inherits properties from its prototype, you can override those inherited properties by assigning new values directly to the child object. This creates own properties that shadow the prototype properties. Understanding Property Inheritance When you create an object using Object.create(), the new object inherits properties from its prototype. These inherited properties can be overridden by setting properties directly on the derived object. Example: Overriding Derived Properties Override Derived Properties ...
Read MoreWhy can't my HTML file find the JavaScript function from a sourced module?
When an HTML file cannot find JavaScript functions from a sourced module, it's usually because the function isn't properly exported from the module or the import statement is incorrect. ES6 modules require explicit export/import statements to share functions between files. The Export Problem Functions in JavaScript modules are not globally accessible unless explicitly exported. Without the export keyword, functions remain private to the module. demo.js console.log("function will import"); export function test(){ console.log("Imported!!!"); } Example: Complete Module Import index.html ...
Read MoreLooping over matches with JavaScript regular expressions
In JavaScript, you can loop over regular expression matches using several methods. The most common approaches are using match() with the global flag, matchAll(), or exec() in a loop. Using match() with Global Flag The match() method with the global flag (g) returns an array of all matches, which you can then iterate over: Regex Matches Loop body { ...
Read MoreExplain touch events in JavaScript
Touch events in JavaScript are fired when a user interacts with a touchscreen device. These events provide a way to handle touch-based interactions on mobile devices, tablets, and other touch-enabled screens. Touch Event Types JavaScript provides four main touch events for handling different stages of touch interaction: Event Description ...
Read MoreExplain load events in JavaScript?
Load events in JavaScript are fired at different stages of the page lifecycle, from initial DOM construction to complete resource loading and page unloading. Understanding these events helps you execute code at the right time. Types of Load Events Event Description When It Fires DOMContentLoaded DOM tree is built but external resources like stylesheets and images are still loading HTML parsed completely load All resources (images, stylesheets, scripts) are fully loaded Page completely loaded beforeunload User is about to leave the page - can show confirmation dialog ...
Read MoreDisabling arrow key in text area using JavaScript.
You can disable arrow key navigation in a text area using JavaScript by intercepting keydown events and preventing their default behavior. This technique is useful when you want to restrict user interaction or create custom navigation controls. Understanding Arrow Key Codes Arrow keys have specific key codes that we can detect: Left Arrow: 37 Up Arrow: 38 Right Arrow: 39 Down Arrow: 40 Complete Example Disable Arrow Keys in Textarea ...
Read MoreValidating a file size in JavaScript while uploading
File size validation is essential for web applications to prevent users from uploading files that are too large for your server or application limits. JavaScript provides built-in methods to check file size before upload begins. How File Size Validation Works When a user selects a file using an HTML file input, JavaScript can access the file's properties through the files property. The size property returns the file size in bytes, which we can then validate against our requirements. Basic File Size Validation ...
Read MoreUndeclared vs Undefined? In JavaScript
In JavaScript, undeclared and undefined are two different concepts that developers often confuse. Understanding the distinction is crucial for debugging and writing reliable code. Key Differences Undeclared occurs when you try to access a variable that hasn't been declared using var, let, or const. This results in a ReferenceError. Undefined occurs when a variable has been declared but hasn't been assigned a value. The variable exists but contains the special value undefined. Example: Undefined Variable Undefined Variable ...
Read MoreinnerHTML vs innerText in JavaScript.
The innerHTML and innerText properties are two different ways to access and manipulate the content of HTML elements in JavaScript. innerHTML - Returns or sets the HTML markup inside an element, including all tags, formatting, and spacing. It preserves the complete HTML structure. innerText - Returns or sets only the visible text content, stripping out all HTML tags and normalizing whitespace. Key Differences Property HTML Tags Whitespace Hidden Elements innerHTML Preserved Preserved Included innerText Removed Normalized Excluded Example ...
Read More