When you are shopping online and finalizing your order, you usually fill in forms for your name, address, email, and payment method. Sometimes those forms have an asterisk (*) next to them as required fields. Code in which of the following languages can check to make sure all required fields are completed?

a. JavaScript
b. HTML
c. CSS
d. Python

a.JavaScript

Explanation:

Form validation is adopted to prevent the abuse of web form by malicious users, data that are not properly validated causes or leads to security vulnerabilities, thereby making a website to be at a risk of being attacked by malicious users.

Validation rules checks that the data a user enters in a record meets the specify standards before the user is allowed to save the record, a validation rule evaluates the data in one or more fields and return it as true or false.

JavaScript form validation  can be used to check all required fields, the steps are adopted are:

i) Basic validation − The form is first checked to make sure that all the mandatory fields are filled.

ii) Data format validation −The data that is entered is then checked for correct form and value before allowing to proceed, submit or save the record.