Take Test: Symfony 7 – PHP – Object Oriented Programming

Question 1: What is encapsulation in OOP?

Allowing multiple inheritance in a class.

Making all properties public.

Declaring abstract classes.

Grouping data and methods while controlling access to them.

Question 2: Which visibility level allows access only inside the same class?

protected

private

public

internal

Question 3: What does the static keyword mean for class methods?

The method is private by default.

It makes the method immutable.

The method belongs to the class and cannot use $this.

It prevents overriding.

Question 4: How is inheritance implemented in PHP?

Using the extends keyword; PHP supports single inheritance.

Using the inherit keyword; multiple inheritance is supported.

Using the implements keyword for all inheritance.

By copying code from other classes manually.

Question 5: What is polymorphism in OOP?

Using multiple constructors in one class.

Encapsulating properties as private.

Accessing static methods dynamically.

Different classes responding to the same method name in their own way.

Question 6: What are abstract classes used for in PHP?

To define common behavior but prevent direct instantiation.

To allow multiple inheritance.

To store constants only.

To make all methods static.

Question 7: What is the purpose of interfaces in PHP?

To store reusable methods like traits.

To define method signatures that implementing classes must provide.

To prevent method overriding.

To enforce property visibility.

Question 8: How do traits differ from interfaces?

Traits must always implement interfaces.

Traits provide method bodies; interfaces only define signatures.

Traits can only contain constants.

Interfaces can contain concrete methods.

Question 9: What happens if a class uses two traits with the same method name?

The last included trait automatically wins.

PHP throws a fatal error and cannot be fixed.

Both methods execute sequentially.

You must resolve the conflict with insteadof or as.

Question 10: What is late static binding used for?

To delay object creation until runtime.

To prevent overriding of static methods.

To make static methods refer to the called class, not the defining one.

To dynamically create traits.

Question 11: What does the final keyword do for a class or method?

Forces abstract inheritance.

Allows overriding only from traits.

Applies only to interfaces.

Prevents classes or methods from being extended or overridden.

Question 12: What are magic methods in PHP?

Special methods with double underscores triggered by PHP events.

User-defined functions for encryption.

Methods automatically inherited from all classes.

Functions used only in traits.

Question 13: What does the __construct method do?

It initializes the object upon creation.

It destroys the object when out of scope.

It copies another object’s state.

It prevents class instantiation.

Question 14: How can you prevent a class from being instantiated directly?

By removing the constructor.

By setting all properties private.

By declaring it as abstract.

By declaring it as final.

Question 15: What does the __clone method do in PHP?

It destroys the cloned object.

It prevents cloning entirely.

It is called after cloning to modify the new object.

It performs a deep copy automatically.

Question 16: What is an interface segregation principle example?

Using traits instead of inheritance.

Splitting large interfaces into smaller, focused ones.

Combining many interfaces into one.

Avoiding private methods.

Question 17: Which PHP feature supports dependency injection most directly?

Type-hinted constructors and setters.

Global variables.

Static methods.

Interfaces without implementations.

Question 18: What is the purpose of the __autoload or spl_autoload_register functions?

They destroy unused objects.

They serialize classes to JSON.

They make constructors optional.

They automatically load undefined classes when referenced.

Question 19: How do typed properties improve OOP in PHP?

They allow dynamic typing.

They disable property overloading.

They make properties static.

They enforce value types for class properties.

Question 20: What does composition mean in OOP?

Overriding parent class methods.

Using traits in place of inheritance.

Building classes by combining other class instances instead of inheriting.

Creating circular dependencies.