Re: Comparison of For/While Loop

From:

Gordon Beaton <n.o.t@for.email>

Newsgroups:

comp.lang.java.help

Date:

11 Apr 2008 13:57:27 GMT

Message-ID:

<47ff6e47$0$8159$8404b019@news.wineasy.se>

On Fri, 11 Apr 2008 09:20:23 -0400, Lew wrote:

That is not the only use case for the 'for' loop.

for ( Iterator iter = collection.iterator(); iter.hasNext(); ) { ... }

It's bounded, but can you tell me how many times that loop will iterate?

Based on the information provided, there is no indication that the
loop is bounded (other than your statement) since the elements of the
iterator aren't shown to be "consumed" anywhere.

for ( Foo foo = new Foo(); checkForTermination(); foo = new Foo() )
{ ... }

How many times will this one iterate?

The second example is unbound and will iterate until
checkForTermination() is false.

I'm not sure what point you're trying to make here.

I certainly did not imply that "for" can't be used in other ways, only
that it's a good rule to follow when choosing because of the meaning
it conveys to the reader of the program.

Obviously "for" can always be used in place of "while" because it lets
you use an arbitrary boolean expression for the loop condition. That
doesn't mean it's a good idea to do so.

/gordon

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