JAVA Interfaces and Abstract Classes
Which of the following statements regarding abstract classes are true?

A subclass of a non-abstract superclass can be abstract.
A subclass can override a concrete method in a superclass to declare it abstract.
An abstract class can be extended.
All of these
An abstract class can be used as a data type.

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
Given the following piece of code:public interface Guard{ void doYourJob();}abstract public class Dog implements Guard{ }which of the following statements is correct?

This code will compile without any errors.
This code will not compile, because class Dog must implement method doYourJob() from interface Guard.
This code will not compile, because method doYourJob() in interface Guard must be defined abstract.
This code will not compile, because in the declaration of class Dog we must use the keyword extends instead of implements.

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
What will be the output?interface A{public void method();}class One{public void method(){System.out.println("Class One method");}}class Two extends One implements A{public void method(){System.out.println("Class Two method");}}public class Test extends Two{public static void main(String[] args){A a = new Two();a.method();}}

will print Class Two method
Compilation Error
will print Class One method
compiles fine but print nothing
None of these

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
What will happen after compiling this program code?abstract class MyClass{ //line 1 private int a, b; public void call(int a, int b){ this.a = a; this.b = b; System.out.print(a+b); }}public class Test{ public static void main(String args[]){ MyClass m = new MyClass(); //line 2 m.call(12,25); }}

Successful run and print 37
Compilation error due to line 2
Compilation error due to line 1
None of these
Runtime error

ANSWER DOWNLOAD EXAMIANS APP