Question

Which of the following expressions evaluates to false?

class C1 {}

class C2 extends C1 { }

class C3 extends C2 { }

class C4 extends C1 {}

C1 c1 = new C1();

C1 c2 = new C2();

C1 c3 = new C3();

C1 c4 = new C4();


c1 instanceof C1

c2 instanceof C1

c4 instanceof C2

c3 instanceof C1

Answer 1

Answer:

If we analyze the given piece of code, C1, C2, C3 and C4 are 4 classes.

• C1 is the base class and does not derive from any other class.

• C2 is a class which inherits C1.

• C3 is a class which inherits C2 and indirectly inherits from C1.

• C4 is a class which inherits C1 directly. If analyses the instance creation statement,

c1 instance of C1 is valid because the object is created for class C1.

c1 c2 = new C2() is valid once again the object is created for Class C2

c1 c3 = new C3() is invalid because the class C3 directly inherits from C2 and not from C1

c1 c4 = new C4() is valid