Learn Functions Of Core Java
- 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
- 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 };
- 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.
- 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
- 5.Whar is the Default Thread Priority?
- A.
0
- B.
10
- C.
5
- D.
1
- 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';
- 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
- 8.Can we force Garbage Collection(gc) ?
- A.
Yes
- 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.
- 10.Which will contain the body of the thread?
- A.
Run();
- B.
Main();
- C.
Start();
- D.
Stop();
Questions: 30 | Attempts: 2675 | Last updated: Mar 22, 2022
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Sample QuestionConsider the following listed items: A. Employee() { } B. public Employee() { } C. private Employee() { } Consider the following statements: I. no-argument constructor, that does not allow instantiation from within the package II. no-argument constructor, that does not allow instantiation from outside the package III. no-argument constructor Which of the following option gives the exact matches of above listed items and statements? Consider the following listed items: A. Employee() { } B. public Employee() { } C. private Employee() { } Consider the following statements: I. no-argument constructor, that does not allow instantiation from within the package II. no-argument constructor, that does not allow instantiation from outside the package III. no-argument constructor Which of the following option gives the exact matches of above listed items and statements?{
Questions: 45 | Attempts: 668 | Last updated: Mar 21, 2022
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Sample QuestionWhich of the following are uses of Object class?(Choose 3)
Questions: 25 | Attempts: 623 | Last updated: Mar 22, 2022
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Sample QuestionWhich of the following may override a method whose signature is void xyz (float f)?1.void xyz(float f)2.public void xyz(float f3,private void xyz(float f)
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