It's not a secret anymore!
The moose likes Programmer Certification (SCJP/OCPJP) and the fly likes About Do While Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of Customer Requirements for Developers this week in the Jobs Discussion forum!
JavaRanch » Java Forums » Certification » Programmer Certification (SCJP/OCPJP)
Bookmark "About Do While" Watch "About Do While" New topic

About Do While

Animesh Shrivastava
Ranch Hand

Joined: Jul 19, 2004
Posts: 298
Can anyone explain these,
why its giving compilation error:
1) do
// System.out.println("hii");

But when i have something like this, there are no compilation errors:
2) do

Or even when i give something like this i dont get any compilation errors
3) do
Mike Gershman
Ranch Hand

Joined: Mar 13, 2004
Posts: 1272
The key to this problem is that there must be one statement between do and while(...);

In the first, there is no statement.

in the second case, there is one print statement.

In the third case, "while(true);" is treated as a while loop with an empty statement as the body, so "while(true);" is the one statement and "while(false);" is the rest of the do statement.

Mike Gershman
SCJP 1.4, SCWCD in process
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
If you for some reason want to do nothing (at least once) while some condition is true you can write

Ask a Meaningful Question and HowToAskQuestionsOnJavaRanch
Getting someone to think and try something out is much more useful than just telling them the answer.
Don't get me started about those stupid light bulbs.
subject: About Do While
jQuery in Action, 3rd edition