programming languages Online Quiz - 63

Description: programming languages Online Quiz - 63
Number of Questions: 20
Created by:
Tags: programming languages
Attempted 0/20 Correct 0 Score 0

What modifiers may be used with an interface declaration

  1. Public

  2. Private

  3. Abstract

  4. Protected

Correct Option: A,C

The developer can force garbage collection by calling System.gc().

  1. True

  2. False

Correct Option: B

Assertions are used to enforce all but which of the following?

  1. Preconditions

  2. Postconditions

  3. Exceptions

  4. Class invariants

Correct Option: C

Which of the following keywords is used to invoke a method in the parent class?

  1. this

  2. super

  3. final

  4. static

Correct Option: B

The following line of code is valid. int x = 9; byte b = x;

  1. True

  2. False

Correct Option: B

At first JAVA was named as______ .

  1. Fusion

  2. Gabriel

  3. Oak

  4. Globe

Correct Option: C

A lock can be acquired in a class.

  1. True

  2. False

Correct Option: A

Garbage collection guarantee that a program will not run out of memory.

  1. True

  2. False

Correct Option: B

What is the purpose of the Runtime class?

  1. To provide access to the Java runtime system.

  2. To avoid run time exception.

  3. To provide the capability to execute code no matter whether or not an exception is thrown or caught.

  4. Both 2 & 3

Correct Option: A

Which containers may have a MenuBar?

  1. Panel

  2. Frame

  3. Class

  4. JVM

Correct Option: B

Can a Byte object be cast to a double value?

  1. True

  2. False

Correct Option: B

AI Explanation

To answer this question, we need to understand the concept of casting and the data types involved.

In Java, casting is the process of converting a value from one data type to another. However, there are certain restrictions on which types can be cast to each other.

A byte is an 8-bit signed integer data type, while a double is a 64-bit floating-point data type. These two data types are not directly compatible, and casting a Byte object to a double value is not allowed.

Therefore, the correct answer is:

B. False - A Byte object cannot be cast to a double value.

A class inherit the constructors of its superclass?

  1. True

  2. False

Correct Option: B

Checked Exceptions are

  1. all sub-classes of Throwable

  2. not the sub classes of RuntimeException

  3. all sub-classes of Error

  4. None of these

Correct Option: B

Which class is the immediate superclass of the Container class?

  1. Frame

  2. Component

  3. Public

  4. Super

Correct Option: B

class test{} class tester extends test{ public static void main(String[] args) { test t1 = new tester(); test t2 = new test(); tester t3 = new tester(); System.out.println( t1 instanceof tester); System.out.println( t2 instanceof tester); System.out.println( t3 instanceof tester); System.out.println( t1 instanceof test); System.out.println( t2 instanceof test); System.out.println( t3 instanceof test); }

  1. True False True True True True

  2. True False False True True True

  3. True False True True True False

  4. True False True True False True

Correct Option: A

public class Fun { public static void main(String[] args){ int x=0; boolean b=true; String str; str=(b)?"success": (x=0)?"Failure":"Neither"; System.out.println(str); } }

  1. Failure

  2. success

  3. Exception will be thrown

  4. Compilation error

  5. Neither

Correct Option: D

class Root { int bark=10; public void get(){ System.out.println("Root"); } } public class Tree extends Root{ public void get(){ bark =15; System.out.println("Tree"); } public static void main(String[] args){ Tree t = new Tree(); Root r = new Root(); Root t1= new Tree(); r.get(); t.get(); t1.get(); System.out.println(t.bark); System.out.println(t1.bark); System.out.println(r.bark); } }

  1. Root Tree Tree 15 15 15

  2. Root Tree Tree 10 15 15

  3. Root Tree Root 15 15 10

  4. Root Tree Tree 15 15 10

  5. Root Tree Tree 15 10 10

Correct Option: D

public class Top { private int i; Top(int i) {this.i=i; } public int getValue(){ return this.i; } } class Bottom{ public static void main(String[] args) { Top tp = new Top(5); String j = Integer.toString(tr.getValue()); tp.i=15; System.out.println( tp.i + j); } }

  1. 155

  2. Compilation error

  3. Exception

  4. 20

  5. 5 5

Correct Option: B

public class Play { public static void main(String[] args) { int[][] a = {{5,2,4,7}, {9,2}, {3,4}}; int[] b = a[1]; int[][] b1= new int[3][]; int a2 = b[2]; System.out.println(a2); } }

  1. 2

  2. 4

  3. Exception

  4. Compilation error

  5. 9

Correct Option: C
- Hide questions