Front-end Validation

Frontend or client-side validation is the process of alerting the user about issues in the form before they send it ahead to the server. This process provides a great user experience in our application because the user is immediately made aware of any problematic data. Such a validation process helps save money and resources as well.

The validation is carried out with built-in HTML5 features as well as JavaScript for any customization purposes. These might include customizing the validation or performing complex validation procedures. So, we will focus on JavaScript form validations in this lesson.

The form

First things first, let’s create a basic form.

Our form has three required input fields. For a better user experience, we’ve added the rules that must be followed by the user.

Now what we want to do is set the font color in such a way that it defaults to red when the current input —the one that has ...