Log In Register

Units


Observable & Timer Class - Questions and Answers

 

Practice these Observable & Timer Class under Java Programming walk-in interview Questions/ examination questions with best tricks and short cuts with solution. Student (candidate) who want to crack the walk in interview, competitive exams and want to find short cuts and tricks to solve questions on Observable & Timer Class for following purpose.


– Anyone who is wishing to increase their perfect knowledge of Observable & Timer Class of Java Programming.
– Anyone who is preparing for aptitude test and increase his in depth aptitude knowledge Java Programming specifically Observable & Timer Class.
– Anyone who is preparing for interviews (competitive examinations, govt examinations and bank examinations, off-campus or on campus interviews, walk-in interview and company interviews) having questions on Observable & Timer Class under Java Programming.

– Anyone who is preparing for aptitude test or competitive exam or entrance exam.
– Anyone who is preparing for entrance examinations and other competitive examinations.
– All Experienced, Freshers and Students.

Here is list of Questions and Answers covering all key area of  Observable & Timer Class topic of Java Programming:

 

1. What is use of Observable class?

Answer: Option B

Explanation:
The Observable class is used to create subclasses that other part of program can observe.

2. Which of these methods is called when observed object has changed?

Answer: Option D

Explanation:

3.  Which of these methods calls update() method?

Answer: Option D

Explanation:
notifyObserver() notifies all the observers of the invoking object that it has changed by calling update(). A null is passed as the second argument to update().

4. Which of these methods is used to notify observer the change in observed object?

Answer: Option A

Explanation:

5.  Which of these interfaces is implemented by TimerTask class?

Answer: Option A

Explanation:

6. Which of these package provides the ability to read and write in Zip format?

Answer: Option C

Explanation:

7.  Which of these classes can schedule task for execution in future?

Answer: Option B

Explanation:
Timer and TimerTask are the classes that support the ability to schedule tasks foe execution at some future time.