rtti

Quiz Guidelines

 

Descriptive Question

QID: 
39

Given:

public class X implements Z {

public String toString() {

return "I am X";

}

public static void main(String[] args) {

Y myY = new Y();

X myX = myY;

Z myZ = myX;

System.out.println(myZ);

}

}

class Y extends X {

public String toString() {

return "I am Y";

}

}

interface Z {}

What is the reference type of myZ and what is the type of the object it references? 

Multiple Choice Question

QID: 
37

Given:

interface I {
}

class A implements I {
}

class B extends A {
}

class C {
}

public class TestClass1 {
	public static void main(String[] args) {
		I i = new B();
		B b = new B();
		C c = new C();
		if (i instanceof I)
			System.out.println("i is a I");
		if (b instanceof A)
			System.out.println("b is a A");
		if (c instanceof A)
			System.out.println("c is a A");
	}
}

 

What will be printed when the above code is compiled and run?

Select 1 option

A. It will not compile.

B. It will throw an exception when run.

C. i is a I
    b is a A

D. i is a I

E. b is a A

F. c is a A

Multiple Choice Question

QID: 
34

Given

class TestClass{

public static void main(String[] args){

A a = new A();

B b = new B();

};

}

class A implements T1, T2{}

class B extends A implements T1{}

interface T1 { }

interface T2 { }

Select 4 options

A. (a instanceof T1) will return true.

B. (a instanceof T2) will return true.

C. (b instanceof T1) will return true.

D. (b instanceof T2) will return true.

E. (b instanceof A) will return false.