Now we will see how we can validate our entered form data before submitting it to the web server.The following example shows how to validate an entered email address.Then we use a property called validity from validation API to get the error of each input field.The validity property gets a validity State object with the information of which validations failed and which didn’t.This was really a lengthy process which used to put a lot of burden on the server.Java Script provides a way to validate form's data on the client's computer before sending it to the web server. First let us see how to do a basic form validation.The name can’t be empty and password can’t be less than 6 characters long. The user will not be forwarded to the next page until given values are correct.In this document, we have discussed Java Script Form Validation using a sample registration form.
Ideally, users fill in the form with necessary information and finish the job successfully. These requirements turned into the main characteristics of this solution: element (type=email, number, …), we also have constraint validation (required, maxlength, …) to ease the work of checking the form content on the client side.Now, when you have finished learning how to validate a sample registration form using Java Script, let us take you to the another way doing the same thing.But this time, the instead of on submitting the form, validations are on field level, i.e. Sure that will be preety interesting to learn and share as well.For the sake of demonstration, we have taken five countries only. CSS Code of the Sample Registration Form The code above checks whether a sex is selected. If Male or Female is selected, it generates an alert saying that the form is successfully submitted and it reloads the form.Flowchart: Here is the entire Java Script used for validation of the form.