JAVA INHERITENCE QUIZ

What will be the output for the below code ?public interface TestInf{ int i =10;}public class Test{ public static void main(String... args){ TestInf.i=12; System.out.println(TestInf.i); }}

12

Runtime Exception

10

None of these

Compile with error

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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 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.

This code will not compile, because class Dog must implement method doYourJob() from interface Guard.

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Which of the following class definitions defines a legal abstract class?

class A { abstract void unfinished(); }

abstract class A { abstract void unfinished(); }

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

class A { abstract void unfinished() { } }

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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) }}

2 and 3

4 and 5

3 and 4

1 and 3

1 and 2

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Which of the following statements regarding abstract classes are true?

All of these

An abstract class can be used as a data type.

A subclass can override a concrete method in a superclass to declare it abstract.

A subclass of a non-abstract superclass can be abstract.

An abstract class can be extended.

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Which of the following is a correct interface?

interface A { void print() { } }

abstract interface A { print(); }

interface A { void print(); }

abstract interface A { abstract void print(); { }}

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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. }

Compilation fails due to an error on line 8

null

None of these

A

Compilation fails due to an error on line 3

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Which two of the following are legal declarations for abstract classes and interfaces?1. final abstract class Test {}2. public static interface Test {}3. final public class Test {}4. protected abstract class Test {}5. protected interface Test {}6. abstract public class Test {}

2 and 4

5 and 6

1 and 2

3 and 5

3 and 6

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Runnable is a _____ .

method

vaiable

abstract class

interface

class

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Determine output of the following code.interface A { }class C { }class D extends C { }class B extends D implements A { }public class Test extends Thread{ public static void main(String[] args){ B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); }}

b is an instance of

Nothing.

b is an instance of A followed by b is an instance of

b is an instance of

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