1. What is Object-Oriented Programming?

2. Objects – Variables and Logic inside "Objects", not standalone code – Objects contain related variables and functions Key Concepts – Encapsulation – Inheritance – Polymorphism

3. Key Terminology – Functions defined in an Object are called "Methods" – Variables defined within an Object (not inside functions) are called "Properties" of the Object – An Object is built (or instantiated) from a "class" that defines what is contained in an Object – A class can inherit properties and methods from another class – An abstract class can be inherited by another class, but not instantiated – An interface can contain constants and method definitions that can be implemented by other classes

4. A Simpler Way To Think About Object-Oriented Programming "Objects are defined by a meaningful name that keeps related functions and variables together in one place" Example: – A Payroll object would contain a variable holding a check number and a function that would calculate the withholding tax on a paycheck – Payroll>checkNumber – Payroll>calcWithholdingTax()

5. What's Missing in PHP compared to other OOP Languages? – PHP's data weakly typed – PHP's objects are not explicitly typed No object detection (polymorphism problem) – No way to instantiate an object of one type into an object of a supertype – Functions do not enforce a particular data type that must be returned

6. End of Presentation