Form validation is the process of checking whether user input is correct before it is processed.
Validation helps prevent errors, improves user experience, and ensures that collected data is meaningful.
Why Form Validation Is Important
Without validation, users can submit incomplete or incorrect data.
This can lead to system errors, poor user experience, and security risks.
Where Form Validation Is Used
Form validation is used in:
- Login forms
- Registration forms
- Contact forms
- Payment forms
Types of Form Validation
There are two main types of form validation:
- Client-side validation
- Server-side validation
Client-side validation happens in the browser before data is sent to the server.
Server-side validation happens on the server after the form is submitted.
In this example, the form allows submission even if the input field is empty.
This can cause issues when processing data.
The required attribute ensures that the user must fill the field before submitting the form.
Benefits of Using Validation
- Reduces incorrect submissions
- Improves data quality
- Saves server processing time
- Improves user trust
Form Validation and Security
Validation helps reduce security risks but does not replace server-side checks.
Always validate important data on the server as well.
Why Form Validation Matters for Jobs
Almost every real-world application uses validated forms.
Employers expect developers to understand validation basics.
Practice Task
Create a simple form with at least two required fields and test validation in the browser.
What You Will Learn Next
In the next lesson, you will learn about required fields and input constraints.