To make a variable shared across all objects of a given class, which keyword do you use?
Objects are always passed by reference: true or false?
Given that dog is a class, poodle is a class inheriting from dog, and $poppy is an object of class poodle, would $poppy be considered an instance of the class dog when using the instanceof keyword?
To list all classes currently available to your script, which function should be used:
Instanceof and is_subclass_of() are identical: true or false?
Which of the following statements are true about interfaces:
a) They allow you to force classes to implement a set of functions
b) They can be based on other interfaces
c) They can be based on other classes
d) They are faster than using class inheritance
e) All of the above
When must the "override" keyword be used:
a) Whenever a child class overrides a function inherited from its parent
b) Whenever a child class inherits from an interface
c) Whenever a child class implements an interface and inherits from a parent class
Objects of an abstract class can only be created when the class is declared final: true or false?
Copyright ©2015 Paul Hudson. Follow me: @twostraws.