What is the main benefit of using a function?
How many values can a function return?
What is the difference between accessing a variable by name and by reference?
What is the meaning of “scope” in PHP?
How can you incorporate one PHP file within another?
How is an object different from a function?
How do you create a new object in PHP?
What syntax would you use to create a subclass from an existing one?
How can you call an initializing piece of code when an object is created?
Why is it a good idea to explicitly declare properties within a class?