This document provides examples of using different PHP features including strings, arrays, functions, classes, objects, and form validation. It includes 12 examples demonstrating various PHP concepts. The first example shows string manipulation functions. The second demonstrates arrays and array functions. The third calculates a factorial using a user-defined function. Subsequent examples generate an employee payslip using classes and objects, build a student mark entry interface, perform hotel room booking with advanced controls, and validate form data on the client and server sides.