Which is an example of runtime polymorphism?

A) Method overloading B) Operator overloading C) Method overriding D) Constructor chaining

What happens if a subclass defines a method with the same name, parameters, but a different return type as its superclass?

A) It will override successfully B) It causes a compile-time error C) The method is ignored D) Java automatically converts the return type

Which of the following best describes encapsulation in Java?

A) Hiding implementation details and restricting access using access modifiers B) Inheriting properties from another class C) Writing multiple methods with the same name but different parameters D) Converting primitive types into objects

Which statement about abstract classes and interfaces is true?

A) Interfaces can have constructors B) Abstract classes cannot have methods with bodies C) Interfaces can have static and default methods D) Abstract classes must implement all methods

Can constructors be inherited in Java?

A) Yes, always B) Only if marked as public C) No, but they can be called using super() D) Yes, if the subclass has no constructor

Which of the following is true about method overloading and overriding?

A) Overloading occurs across different classes B) Overriding must change the method name C) Overloading is compile-time polymorphism; overriding is runtime polymorphism D) Both require @override annotation

What does the super keyword refer to in Java?

A) The current class B) The superclass object C) The main method D) A static variable

Which of these uses of final is incorrect?

A) final class cannot be subclassed B) final method cannot be overridden C) final variable can be reassigned once initialized D) final can be used for constants

What happens if a static method tries to access a non-static variable directly?

A) It will compile but throw a runtime error B) It will compile successfully C) It causes a compile-time error D) The variable is automatically made static

Can you create an object of an abstract class?

A) Yes, using the new keyword B) No, but you can use it through a subclass C) Yes, if all abstract methods are implemented D) Yes, but only within the same package

If two interfaces have the same default method name and a class implements both, what must be done?

A) Nothing — Java picks one automatically B) The class must override the method to resolve conflict C) It causes a runtime exception D) The class can’t implement both interfaces

Which of the following is not a commonly overridden method from the Object class?

A) equals() B) toString() C) hashCode() D) main()

Why might composition be preferred over inheritance?

A) It allows multiple inheritance B) It provides more flexibility and reduces dependency C) It makes all fields public D) It automatically overrides all superclass methods

Which access modifier allows visibility only within the same package?

A) private B) public C) protected D) default (no modifier)

How does Java decide which overridden method to call when a superclass reference points to a subclass object?

A) At compile time B) At runtime using dynamic binding C) Based on the return type D) By the JVM during class loading