Inheritance and Polymorphism – Multiple Choice Questions (MCQs)

1. 37. What is the output of the following code? `interface MyInterface {} class MyClass implements MyInterface {} public class InstanceOfInterfaceDemo { public static void main(String[] args) { MyClass obj = new MyClass(); System.out.println(obj instanceof MyInterface); } }`

   • A. TRUE
   • B. FALSE
   • C. Error
   • D. None

2. 38. What is the significance of the `Object` class in Java's inheritance hierarchy?

   • A. It is the superclass of all classes
   • B. It is the only class that cannot be subclassed
   • C. It represents primitive data types
   • D. It is an interface

3. 39. Which methods are inherited by all Java objects from the `Object` class?

   • A. `toString()`
   • B. `equals()`
   • C. `hashCode()`
   • D. `clone()`

4. 40. What is the purpose of the `toString()` method inherited from the `Object` class?

   • A. To compare two objects
   • B. To get the hash code of an object
   • C. To return a string representation of the object
   • D. To create a copy of the object

5. 41. What is the purpose of the `equals()` method inherited from the `Object` class?

   • A. To return a string representation of the object
   • B. To compare two objects for equality
   • C. To get the hash code of an object
   • D. To create a copy of the object

6. 42. What is the purpose of the `hashCode()` method inherited from the `Object` class?

   • A. To return a string representation of the object
   • B. To compare two objects for equality
   • C. To return a hash code value for the object
   • D. To get the class of the object

7. 43. What is the purpose of the `clone()` method inherited from the `Object` class?

   • A. To return a string representation of the object
   • B. To compare two objects for equality
   • C. To get the hash code of an object
   • D. To create a shallow copy of the object