JavaQuizzes

Quiz Guidelines

 

Multiple Choice Question

QID: 
502

What, if anything, is wrong with the following code?

interface T1{
}
interface T2{
   int VALUE = 10;
   void m1();
}
interface T3 extends T1, T2{
   public void m1();
   public void m1(int x);
}

Select 1 option

A. T3 cannot implement both T1 and T2 because it leads to ambiguity.
B. There is nothing wrong with the code.
C. The code will work fine only if VALUE is removed from T2 interface. 
D. The code will work fine only if m1() is removed from either T2 and T3.
E. None of the above.

Multiple Choice Question

QID: 
503

Which one of these is a proper definition of a class TestClass that cannot be subclassed?

Select 1 option

A. final class TestClass { }
B. abstract class TestClass { }
C. native class TestClass { }
D. static class TestClass { }
E. private class TestClass { }

Multiple Choice Question

QID: 
504

Which of the following statements are acceptable?

Select 4 options

A. Object o = new java.io.File("a.txt");  (Assume that java.io.File is a valid class.)
B. Boolean bool = false;
C. char ch = 10;
D. Thread t = new Runnable() ;(Assume that Runnable is a valid interface.) 
E. Runnable r = new Thread();  (Assume that Thread is a class that implements Runnable interface)

Multiple Choice Question

QID: 
505

A java source file contains the following code:

interface I {
int getI(int a, int b);
}
interface J{
int getJ(int a, int b, int c);
}
abstract class MyIJ implements J , I { }
class MyI{
int getI(int x, int y){ return x+y; }
}
interface K extends J{
int getJ(int a, int b, int c, int d);
}

Identify the correct statements:

Select 1 option

A. It will fail to compile because of MyIJ
B. It will fail to compile because of MyIJ and K
C. It will fail to compile because of K
D. It will fail to compile because of MyI and K
E. It will fail to compile because of MyIJ, K, and MyI
F. It will compile without any error.

Multiple Choice Question

QID: 
506

Which one of the following class definitions is/are a legal definition of a class that cannot be instantiated?

class Automobile{
abstract void honk(); //(1)
}
abstract class Automobile{
void honk(); //(2)
}
abstract class Automobile{
void honk(){}; //(3)
}
abstract class Automobile{
abstract void honk(){} //(4)
}
abstract class Automobile{
abstract void honk(); //(5)
}

Select 2 options

A. 1
B. 2
C. 3
D. 4
E. 5

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