From: "jwmerrill@..." <jwmerrill@...>
Date: 2008-03-03T23:54:58+09:00
Subject: Re: Normal For Loop

On Mar 3, 9:37 am, Cory Cory <cg821...@ohio.edu> wrote:
> I tried to do this the other night, but right now I can't find a good
> example so here it goes:
>
> a = some_array
> minValue = 999999
> for(i=0; i<a.length && minValue!=0; i+=1) {
>    minValue = (5000 - a[i]).abs
>
> }

What does this example do exactly?  It seems to run until it finds a
value in a that is equal to 5000, and then stop without reporting
anything.

a.detect {|n| 5000 == n}

or

a.any? {|n| 5000 == n}

See, this is actually more concise and readable, I think.

> This isn't the best example.  However, there are many times like the
> loop above where I want to go through the whole thing, but if I find
> exactly what I am looking for, I want to bail out early instead of
> wasting that processing time.
>
> Also, I sometimes may want to not actually iterate straight through, but
> browse through the array in some more complex order.

The point is not that no examples exist, but that they realistically
don't come up very much.  Get familiar with the methods in Enumerable,
Array, and Numeric.  Each time you want to write a for loop, try and
use one of those instead, and if you get stuck, ask for advice.
You're solution will almost always be more readable, and maybe 1 time
in 100 you'll need to use a while loop.

JM