From: William James <w_a_x_man@...>
Date: 2008-03-02T14:54:54+09:00
Subject: Re: counting in for .. in ..



William James wrote:
> On Mar 1, 4:24 pm, Daniel Liebig <d.lie...@wevin.de> wrote:
> > Hi,
> >
> > i'm doing my first steps in ruby (on rails) and often use things like
> >
> > for thing in @several_things
> >   print thing
> > end
> >
> > Ok so far, looks great :)
> >
> > But i often need a counter inside of the loop, may it be to create row
> > colors or other stuff. What i end up with then is:
> >
> > i = 0
> > for thing in @several_things
> >   print thing + " No. " + i.to_s
> >   i += 1
> > end
> >
> > Pardon me, but this is ugly, compared to the first clean lines. So far i
> > know ruby as an elegant language, so i wouldn't be surpised if there'd
> > be any kind of implemented counter in the for loop or a smarter way to
> > implement it.
> >
>
>
> E:\>irb --prompt xmp
> a = %w(zero one two three)
>     ==>["zero", "one", "two", "three"]
> a.each_with_index{|x,i| puts "Item no. #{i} is #{x}."}
> Item no. 0 is zero.
> Item no. 1 is one.
> Item no. 2 is two.
> Item no. 3 is three.
>     ==>["zero", "one", "two", "three"]

puts a.zip((0...a.size).to_a).map{|a| "Item #{a[1]} is #{a[0]}"}
Item 0 is zero
Item 1 is one
Item 2 is two
Item 3 is three