For example, if you have set length limit in the database for a text input, it is better to do the validation before it actually gets cut off by the database system or even getting an error thrown.
Often, people confuse form validations with form security.
This is done by using validation attributes on form elements.
Validation attributes allow you to specify rules for a form input, such as whether a value must be filled in; the minimum and maximum length of the data; whether the data needs to be a number, an email address, or something else; and a pattern that the data must match.
When you have fields like name or email as mandatory in the form, it should be checked in the server side script as well. Here is the sample output from that script: Note that the “Filling” checkbox group in the HTML form results in an array in the PHP script The rest of the fields appear as simple name-value pairs To validate mandatory fields, we just have to check the presence of the value in the $_POST array.Note that ARIA is an independent specification that's not specifically related to HTML5.Client-side form validations help in giving immediate feedback to the user.Watch the full course on Linked In Learning Start your free month on Linked In Learning, which now features 100% of courses.Develop in-demand skills with access to thousands of expert-led courses on business, tech and creative topics.