PHP PHP Object-Oriented Programming 2

Question 1

What does the abstract keyword mean when applied to a PHP class?

Accepted Answer

The class cannot be instantiated directly

Answer

An abstract class cannot be instantiated on its own and must be subclassed before use.

Question 2

What does an interface in PHP define?

Accepted Answer

A contract of methods that implementing classes must define

Answer

An interface declares method signatures without implementation, and any class that implements it must provide concrete implementations.

Question 3

Which keyword allows calling a PHP method without creating a class instance?

Accepted Answer

static

Answer

The static keyword allows properties and methods to belong to the class itself rather than instances, callable via ClassName::method().

Question 4

How do you call the parent class's constructor from a child class in PHP?

Accepted Answer

parent::__construct()

Answer

parent::__construct() explicitly calls the parent class's constructor from within the child class.

Question 5

What does the final keyword prevent when applied to a PHP method?

Accepted Answer

Child classes from overriding the method

Answer

A final method cannot be overridden in any subclass, locking its behavior.

PHP - PHP Programming Language Practice Test