JAVA Interfaces and Abstract Classes
What is the output for the below code ?interface A{ public void printValue();}1. public class Test{2. public static void main (String[] args){3. A a1 = new A(){4. public void printValue(){5. System.out.println("A");6. }7. };8. a1.printValue();9. }10. }

null
None of these
Compilation fails due to an error on line 3
A
Compilation fails due to an error on line 8

ANSWER DOWNLOAD EXAMIANS APP

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

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

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
Which of the following class definitions defines a legal abstract class?

class A { abstract void unfinished() { } }
public class abstract A { abstract void unfinished(); }
class A { abstract void unfinished(); }
abstract class A { abstract void unfinished(); }

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();}}

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

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
Runtime error
Compilation error due to line 2
Compilation error due to line 1
None of these

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON JAVA Interfaces and Abstract Classes