use of the synchronized (Marcus)

[Cathy Song]

Which of the following best describes the use of the synchronized keyword?
1) Allows two process to run in paralell but to communicate with each other
2) Ensures only one thread at a time may access a method or object
3) Ensures that two or more processes will start and end at the same time
4) Ensures that two or more Threads will start and end at the same time
Answer: 2
Why not 1 also? Thanks.

[Jim Yingst]

For one thing, (1) says "processes" rather than "threds", which is incorrect. Even if it said "threads" though, (1) is somewhat vague, and the question does ask for which of the following best describes synchronized. That generally implies that you should chose only one answer, and (2) is better than (1), so choose (2).

[Cathy Song]

Ahh, I see..
Thanks Jim.