Online Java Programming Test

Posted in: Core Java Test 1
Core Java

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

Java.util.Map

Java.util.List

Java.util.Set

Java.util.Collection
2. Which one creates an instance of an array?

float fa = new float[20];

char[ ] ca = "Some String";

int[ ] ia = new int[15];

int ia[ ] [ ] = { 4, 5, 6 }, { 1,2,3 };
3. Which of the following statements about the hashcode() method are incorrect?

The value returned by hashcode() is used in some collection

The hashcode() method is required to return a positive int value.

The hashcode() method in the String class is the one inherited from Object.

Two new empty String objects will produce identical hashcodes.
4. static int Count = 2; ++Count value?
0

1

2

3
5. Whar is the Default Thread Priority?

0

10

1

5
6. Which will contain the body of the thread?
main();

run();

start();

stop();
7. Which is a invalid declarations of a String?

String s1 = null;

String s2 = new String("JavaStuff");

String s3 = "JavaStuf";

String s4 = (String) 'JavaStuff';
8. Which statement is true?

Any statement that can throw an Exception must be enclosed in a try block.

Any statement that can throw an Error must be enclosed in a try block.

The Error class is a RuntimeException.

catch(X x) can catch subclasses of X where X is a subclass of Exception.
9. How to call parent Class Constructor?

this( );

super.parent( );

this( ). parent( );

super( );
10. Can we force Garbage Collection(gc) ?

Yes

No

Can' Say

Depend's on JVM

If you have any Test Questions please mail to sanjana@javastuff.in