JavaScript Reference and Tutorials
Last updated: August 27, 2026. JavaScript adds behavior, data processing, and interaction to web pages. Use this guide to learn…
Category: JavaScript
Focus the First Available Form Control
Last updated: August 27, 2026. Prefer autofocus for one known field. For dynamic forms, find the first visible, enabled control.…
How to Disable Enter-Key Form Submission with JavaScript
Last updated: August 29, 2026. Pressing Enter in a form can trigger its default submit button. Keep that behavior for…
JavaScript Form Validation
Last updated: August 27, 2026. Start with HTML validation attributes and add JavaScript only for rules built-in constraints cannot express.…
JavaScript Conditional Statements
Last updated: August 26, 2026. JavaScript uses if, else if, and switch to choose which code runs. if and else…
JavaScript Loops and Iteration
Last updated: August 27, 2026. JavaScript loops repeat a block of work. Choose the loop form that makes the stopping…
JavaScript Functions
Last updated: August 27, 2026. A function groups reusable behavior, accepts parameters, and can return a value. Variables declared inside…
JavaScript Arrays
Last updated: August 27, 2026. An array is an ordered, zero-indexed collection. Use an object or Map for named keys…
JavaScript Variables: const, let, and Scope
Last updated: August 27, 2026. Use const unless a binding must be reassigned; use let for a value that changes.…
Your First JavaScript Program
Last updated: August 27, 2026. Load JavaScript as a module and update the DOM with textContent. HTML JavaScript Module scripts…