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Groups > comp.lang.java.programmer > #10534

Re: for :each style question

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On 11/30/2011 6:28 PM, Arne Vajhøj wrote:
> On 11/30/2011 6:32 PM, Roedy Green wrote:
>> In a for:each loop, sometimes you want to treat the first and or last
>> element specially.
>>
>> The obvious way to handle is to revert to a for int i= loop and check
>> for special values of i.
>>
>> You can keep the for:each style if you have a boolean first= true that
>> you set false to detect the first.
>>
>> I don't know of an equivalent way to detect the last.
>>
>> In the olden days I would have handled the first and last cases
>> outside the loop, with the loop running over the middle elements. You
>> can't do that with for:each.
>>
>> What do you consider the best style to deal with this?
>
> first
> for first+1 to last-1
> last
>
> Not much point in for(each) when it in fact is not for each.
>

While it's not a Java for:each loop, it's well within the concept of for 
each loops in general. The JSTL foreach element has some optional syntax 
for accessing just this kind of data :

    <c:forEach var="person" items="${group.members}" varStatus="status">
      ...
    </c:forEach>

Inside the forEach, status can tell you if you're first, last, etc.

    http://www.ibm.com/developerworks/java/library/j-jstl0318/

There are a couple of things I wish Java's for:each did. The other 
biggie is looping across several collections in parallel.

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Thread

for :each style question Roedy Green <see_website@mindprod.com.invalid> - 2011-11-30 15:32 -0800
  Re: for :each style question Arne Vajhøj <arne@vajhoej.dk> - 2011-11-30 19:28 -0500
    Re: for :each style question Chris Riesbeck <Chris.Riesbeck@gmail.com> - 2011-12-05 14:28 -0600
  Re: for :each style question Knute Johnson <nospam@knutejohnson.com> - 2011-11-30 16:49 -0800
    Re: for :each style question Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-11-30 18:23 -0800
      Re: for :each style question Wanja Gayk <brixomatic@yahoo.com> - 2011-12-10 13:28 +0100
        Re: for :each style question Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-12 12:07 -0800
          Re: for :each style question Roedy Green <see_website@mindprod.com.invalid> - 2011-12-13 08:08 -0800
            Re: for :each style question Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-13 12:07 -0800
          Re: for :each style question Wanja Gayk <brixomatic@yahoo.com> - 2011-12-17 16:20 +0100
        Re: for :each style question Jim Janney <jjanney@shell.xmission.com> - 2011-12-14 14:31 -0700
          Re: for :each style question Lew <lewbloch@gmail.com> - 2011-12-14 16:53 -0800
            Re: for :each style question Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-15 16:16 -0800
          Re: for :each style question Wanja Gayk <brixomatic@yahoo.com> - 2011-12-17 12:31 +0100
  Re: for :each style question Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-30 21:35 -0500
  Re: for :each style question Lew <lewbloch@gmail.com> - 2011-11-30 19:12 -0800
  Re: for :each style question Robert Klemme <shortcutter@googlemail.com> - 2011-12-01 23:36 +0100
  Re: for :each style question Steven Simpson <ss@domain.invalid> - 2011-12-04 19:43 +0000

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