HTML form validation can be done by JavaScript. If a form field (fname) is empty, this function alerts a message, and returns false, to prevent the form from being submitted:

Jul 16, 2025 · In this guide, we’ll explore how to perform client-side form validation using pure JavaScript — no frameworks like React or Vue required. Let’s dive in! Why Is Form Validation Important?...

Jan 9, 2025 · In this article, we will guide you through creating a form validation application. This application will validate essential fields such as firstName, lastName, userName, email, and password.

JavaScript provides a way to validate form's data on the client's computer before sending it to the web server. Form validation generally performs two functions. Basic Validation − First of all, the form must …

Feb 1, 2020 · These days, JavaScript provides a number of ways to validate a form's data right in the browser before sending it to the server. Here's the HTML code we'll use in the following examples:

Mar 9, 2025 · However, forms can also be a security risk if not validated properly. In this tutorial, we'll explore the basics of form validation using JavaScript and show you how to create a simple form …

In the following section we will take a closer look at how to perform JavaScript form validation and handle any input errors found appropriately and gracefully.

Nov 22, 2025 · We will walk through the steps to create a simple registration form and validate its inputs using Javascript. First, we need to create the basic HTML structure for our registration form. This …

Let’s create Javascript code which will validate our form. In this example, we are going to validate the name, password, e-mail, telephone, subject, and address: let username = document. forms …

Oct 23, 2025 · So in this post, I’ll walk you through how client-side form handling with JavaScript works — step by step — and show you a clean, beginner-friendly example code you can actually use in …