Client-side validation prevents the client from knowing whether the form is okay before reloading a page.
Whereas, Server-side validation is important due to the fact that client-side validation can be completely bypassed by turning off Java Script.
When an element is valid, the following things are true: Adds a custom error message to the element; if you set a custom error message, the element is considered to be invalid, and the specified error is displayed.
This lets you use Java Script code to establish a validation failure other than those offered by the standard constraint validation API.
If you want your web page to look alive and do a lot more than just gawk at you, Java Script is a must.
The fundamental building blocks in Java Script are called as Functions.
No need to write even a single Java Script line for simple form validation.One of the features of HTML5 is the ability to validate most user data without relying on scripts.This is done by using validation attributes on form elements.In Java Script, validation is used to authenticate a user.In this Java Script Validation article, You will learn about form validation in the following sequence: It is a programming language that helps you to implement a complex and beautiful design on web pages.