Form validation is a technical process of checking if the information that a user has entered is correct and if it’s according to the rules provided.
Form Validation is used by almost every application, website, mostly during sign ups and login. The reason for using form validation is to ensure if the user is entering the correct information, and the information is according to the format specified by that particular application.
Validation libraries can be used to carry out client-side form validation. Before client side validation was a thing, web pages reloaded every time a user entered information and if it was wrong they had to input the whole information again. Now on modern web pages if the user inputs the wrong information, an invalid info dialogue appears and the user can just modify the input instead of rewriting everything
It is another lightweight, user-friendly form validator which works cross browser and can deal with all sorts of edge cases. It works with HTML input types such as email, url, text etc and comes with various customizable rules. It uses the new HTML5 types for unsupported web browsers. It also has a flexible error notification system.
It is the form validation library that was created to extend the HTML5 form validation; it’s a script that augments the native HTML5 form validation elements and attributes. With customizable rules, it also allows us to give users immediate feedback when they leave an input field instead of refreshing the page. Fields with errors are revalidated simultaneously as the user types and the error messages are removed immediately as soon as the user inputs valid information.
Data can be of any form in the input form fields. Often, we need to validate data like emails using regex or some information like credit card info. For validating the Credit card information, there is a library out there in the market known as creditCardValidator.js.