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

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); }}

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

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
What happens if the following program is compiled and executed?interface MyInterface{ void display();}interface MySubInterface extends MyInterface{ void display();}public class Test implements MySubInterface{ public void display(){ System.out.print("Welcome to Examveda."); } public static void main(String args[]){ Test t = new Test(); t.display(); }}

The code will lead to a compilation error as declaration of the display method has been provided in two interface.
The code will lead to a compilation error due to public modifier while declaring the display method.
The code will lead to a compilation error as the display method is not declared as abstract.
None of these
The code will compile and execute successfully showing the output Welcome to Examians.

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
interface Base{ boolean m1 (); byte m2(short s);}which two code fragments will compile?1. interface Base2 implements Base {}2. abstract class Class2 extends Base { public boolean m1(){ return true; }}3. abstract class Class2 implements Base {}4. abstract class Class2 implements Base { public boolean m1(){ return (7 > 4); }}5. abstract class Class2 implements Base { protected boolean m1(){ return (5 > 7) }}

1 and 3
1 and 2
3 and 4
4 and 5
2 and 3

ANSWER DOWNLOAD EXAMIANS APP

JAVA Interfaces and Abstract Classes
What will be the output?1. public interface InfA{2. protected String getName();3. }public class Test implements InfA{ public String getName(){ return "test-name"; } public static void main (String[] args){ Test t = new Test(); System.out.println(t.getName()); }}

Compilation succeed but Runtime Exception
Compilation fails due to an error on lines 2
Compilation fails due to an error on lines 1
test-name
None of these

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