Module 9 here explains sanitizing the user input data in forms using PHP regular expressions and other built-in functions. 1) Discusses about super global variable _SERVER. 2) Discusses on PHP built-in function htmlspecialchars( ). 3) Explains usage of Regular Expressions in PHP and usage of built-in function preg_match(). 4) Discusses on Meta characters utilized to form a pattern in a regular expression. 5) Discusses the validation of name and email fields using regular expressions. 6) Hands-on code play with sandbox file to understand working with forms and utilizing regular expressions to sanitize and validate name, email, website, etc. The sandbox files zip for your practice can be downloaded from here, includes CSS file utilized as well: https://1drv.ms/u/s!AsoBus4--D8kgYpOpntfAa5QheFrbQ?e=NmpxYl Welcome to PHP - Complete Guide for Beginners, in this course we will build up step-by-step all skills needed to write PHP code. Hope you find it useful. Please do share, like and subscribe for similar content in the future. Wish you all the best..Mudit