Java interview questions Part22

7.
Using the fragments below, complete the following code so it compiles. Note, you may not have to fill all of the slots.

Code:

class AgedP {
__________ _________ _________ _________ _________
public AgedP(int x) {
_ ________ _ ________ _ ________ _________ ___________
}
}
public class Kinder extends AgedP {
_________ _________ _________ _________ _________ _________
public Kinder(int x) {
_________ _________ _________ _________ ___________() ;
}
}


Fragments: Use the following fragments zero or more times:

AgedP
super
this

(
)
{
}

;



8.
Given:

1. class Plant {
2. String getName() { return "plant"; }
3. Plant getType() { return this; }
4. }
5. class Flower extends Plant {
6. // insert code here
7. }
8. class Tulip extends Flower {}

Which statement(s), inserted at line 6, will compile? (Choose all that apply.)

Flower getType() { return this; }

String getType() { return "this"; }

Plant getType() { return this; }

Tulip getType() { return new Tulip() ;}


9.
Given:

1. class Zing {
2. protected Hmpf h;
3. }
4. class Woop extends Zing { }
5. class Hmpf { }

Which is true? (Choose all that apply.)

Woop is-a Hmpf and has-a zing.

zing is-a Woop and has-a Hmpf.

Hmpf has-a Woop and Woop is-a Zing.

Woop has-a Hmpf and Woop is-a zing.

Zing has-a Hmpf and Zing is-a Woop.


10.
Given:

1. class Programmer {
2. Programmer debug() { return this; }
3. }
4. class SCJP extends Programmer {
5. // insert code here
6. }

Which, inserted at line 5, will compile? (Choose all that apply.)

Programmer debug() { return this; }

SCJP debug() { return this; }

Object debug() { return this; }

int debug() { return 1; }

int debug(int x) { return 1; }

Object debug (int x) { return this; }


11.
Given:

class Uber {
static int y = 2;
Uber(int x) { this(); y = y * 2; }
Uber() { y++; }
}
class Minor extends Uber {
Minor() { super(y); y = y + 3; }
public static void main(String [] args) {
new Minor();
System.out.println(y);
} }

What is the result?

6

7

8

9

Compilation fails.

An exception is thrown.


12.
Which statement(s) are true? (Choose all that apply.)

Cohesion is the OO principle most closely associated with hiding implementation details.

Cohesion is the OO principle most closely associated with making sure that classes know about other classes only through their APIs.

Cohesion is the OO principle most closely associated with making sure that a class is designed with a single, well-focused purpose.

Cohesion is the OO principle most closely associated with allowing a single object to be seen as having many types.


13.
Given:

1. class Dog { }
2. class Beagle extends Dog { }
3.
4. class Kennel {
5. public static void main(String [] arfs) {
6. Beagle bl = new Beagle();
7. Dog dogl = new Dog();
8. Dog dog2 = bl;
9. // insert code here
10. } }

Which, inserted at line 9, will compile? (Choose all that apply.)

Beagle b2 = (Beagle) dog1;

Beagle b3 = (Beagle) dog2;

Beagle b4 = dog2;

None of the above statements will compile.


14.
Given the following,

1. class X { void dol() { } }
2. class Y extends X { void do2() { } }
3.
4. class Chrome {
5. public static void main(String [] args) {
6. X x1 = new X();
7. X x2 = new Y();
8. Y y1 = new Y();
9. // insert code here
10. } }

Which, inserted at line 9, will compile? (Choose all that apply.)

x2.do2( );

(Y) x2. do2( );

((Y)x2).do2();

None of the above statements will compile.