Introduction to Form Field Validation

One of the first types of JavaScript you are likely to need to write for yourself is to validate a form.

Before we start looking at how to validate form fields in JavaScript, let's start by looking at what types of form fields that there are and work out which ones will need to be validated. We also need to think about when to validate the fields. This first form field validation tutorial discusses the basics of HTML forms and how and when we would need to validate them with JavaScript. In subsequent tutorials we will look at how to actually apply validation to fields using JavaScript and where to attach out JavaScript to validate the fields at the right times.

Introduction to Form Field Validation