21. Which of the following is true for Garbage collector thread?
a. GC is a Non daemon thread
b. GC is a Daemon thread
c. GC is a thread with dead state
d. None of the above
Answer: b. GC is a Daemon thread
22. A thread enters into a Dead State when a thread terminates its processing.
a. True
b. False
Answer: a. True
23. Which keyword when applied on a method allow one thread at a time into a method thus allowing to protect data from being corrupted by simultaneous modifications from different threads?
a. synchronized
b. volatile
c. transient
d. native
Answer: a. synchronized
24. Name the Collection interface that is used to represent elements in a sequence.
a. Collection
b. Set
c. List
d. Map
Answer: c. List
25. Is HashTable a sub class of Dictionary?
a. Yes
b. No
Answer: a. Yes
26. Which of the following are true about interfaces?
a. All methods declared inside Java Interfaces are implicitly public and abstract
b. Variables declared in interfaces are implicitly public, static, and final.
c. An interface can extend any number of interfaces.
d. Methods declared in interfaces are implicitly private.
A) a, b, c
B) c, d
C) b, d
D) b, c
Answer: A) a, b, c
27. Which class enables you to read Java objects from an InputStream?
a. Reader
b. File
c. ObjectReader
d. ObjectInputStream
Answer: d. ObjectInputStream
28. The process of creating object from sequence of bytes is called
a. serialization
b. deserialization
c. Threading
d. Marshalling
Answer: b. deserialization
29. Which is best way to say a method is complete and can't be overridden?
a. final
b. static
c. we cant prevent
d. by default it provides
Answer: a. final
30. The default constructor initializes the instance variables declared in the class.
