Quiz: OOP Interview Questions

5 questionsNo time limitPass: 60%+10 XP on first pass

The 20 OOP questions asked most in campus interviews, with crisp answers, real-life examples and the follow-up questions interviewers usually ask next.

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Question 1
Is Java a 100% object-oriented language?
YesNo — it has primitive types and static membersOnly Java 8+Only with Spring

Question 2

What does this print?

class A { int x = 1; int get() { return x; } }
class B extends A { int x = 2; int get() { return x; } }
public class Main {
    public static void main(String[] args) {
        A obj = new B();
        System.out.println(obj.x + " " + obj.get());
    }
}

2 21 21 12 1

Question 3
Can an abstract class have a constructor?
YesNoOnly if it has no abstract methodsOnly in Python
Question 4
Why doesn't Java allow multiple inheritance of classes?
It's slowerTo avoid the diamond problem's ambiguityInterfaces don't exist in JavaBecause of garbage collection
Question 5
A Team holds Player objects created elsewhere; deleting the team doesn't delete players. This is:
CompositionAggregationInheritancePolymorphism