Learn Functions Of Core Java

10 Questions | By Ram132 | Updated: Mar 21, 2022 | Attempts: 166

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1.

Which interface provides the capability to store objects using a key-value pair?
- A.
  
  Java.util.Map
- B.
  
  Java.util.List
- C.
  
  Java.util.Set
- D.
  
  Java.util.Collection
Correct Answer
A. Java.util.Map
2.

Which one creates an instance of an array?
- A.
  
  Float fa = new float[20];
- B.
  
  Char[ ] ca = "Some String";
- C.
  
  Int[ ] ia = new int[15];
- D.
  
  Int ia[ ] [ ] = { 4, 5, 6 }, { 1,2,3 };
Correct Answer
C. Int[ ] ia = new int[15];
3.

Which of the following statements about the hashcode() method are incorrect?
- A.
  
  The value returned by hashcode() is used in some collection classes to help locate objects.
- B.
  
  The hashcode() method is required to return a positive int value.
- C.
  
  The hashcode() method in the String class is the one inherited from Object.
- D.
  
  Two new empty String objects will produce identical hashcodes.
Correct Answer
B. The hashcode() method is required to return a positive int value.
4.

Class Car { static int CarCount = 0; // Declare and initialize // static variable public Car() { CarCount += 1; // Modify the value in the constructor } public static void main (String [] args) { new Car(); new Car(); new Car(); System.out.println(CarCount); } } What is CarCount Value?
- A.
  
  0
- B.
  
  1
- C.
  
  2
- D.
  
  3
Correct Answer
D. 3
5.

Whar is the Default Thread Priority?
- A.
  
  0
- B.
  
  10
- C.
  
  5
- D.
  
  1
Correct Answer
C. 5
6.

Which is a invalid declarations of a String?
- A.
  
  String s1 = null;
- B.
  
  String s2 = new String("JavaStuff");
- C.
  
  String s3 = "JavaStuff"
- D.
  
  String s4 = (String) 'JavaStuff';
Correct Answer
D. String s4 = (String) 'JavaStuff';
7.

Class Parent { public Parent(String s) { System.out.print("B"); } } public class Child extends Parent { public Child(String s) { System.out.print("D"); } public static void main(String [] args) { new Child("C"); System.out.println(" "); } }
- A.
  
  DBC
- B.
  
  DB
- C.
  
  BD
- D.
  
  Compilation fails
Correct Answer
C. BD
8.

Can we force Garbage Collection(gc) ?
- A.
  
  Yes
- B.
  
  No
Correct Answer
B. No
9.

Which statement is true?
- A.
  
  Any statement that can throw an Exception must be enclosed in a try block.
- B.
  
  Any statement that can throw an Error must be enclosed in a try block.
- C.
  
  The Error class is a RuntimeException.
- D.
  
  Catch(X x) can catch subclasses of X where X is a subclass of Exception.
Correct Answer
D. Catch(X x) can catch subclasses of X where X is a subclass of Exception.
10.

Which will contain the body of the thread?
- A.
  
  Run();
- B.
  
  Main();
- C.
  
  Start();
- D.
  
  Stop();
Correct Answer
A. Run();

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Current Version
Mar 21, 2022

Quiz Edited by
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Sep 12, 2011

Quiz Created by
Ram132

Learn Functions Of Core Java

Which interface provides the capability to store objects using a key-value pair?

Which one creates an instance of an array?

Which of the following statements about the hashcode() method are incorrect?

Class Car { static int CarCount = 0; // Declare and initialize // static variable public Car() { CarCount += 1; // Modify the value in the constructor } public static void main (String [] args) { new Car(); new Car(); new Car(); System.out.println(CarCount); } } What is CarCount Value?

Whar is the Default Thread Priority?

Which is a invalid declarations of a String?

Class Parent { public Parent(String s) { System.out.print("B"); } } public class Child extends Parent { public Child(String s) { System.out.print("D"); } public static void main(String [] args) { new Child("C"); System.out.println(" "); } }

Can we force Garbage Collection(gc) ?

Which statement is true?

Which will contain the body of the thread?