From: Robert Klemme <shortcutter@...>
Date: 2012-10-07T16:37:19+09:00
Subject: Re: Extract numbers from an alpha numeric string

On Thu, Oct 4, 2012 at 6:09 PM, Jan E. <lists@ruby-forum.com> wrote:

> So this cannot work. You either have to split the string at the "-" or
> look for numbers with a regex:
>
> input = '1-3-11-7-4-7'
> players = input.split('-').map {|num| h[num.to_i]}
> p players
>
> or
>
> input = '1-3-11-7-4-7'
> players = input.scan(/\d+/).map {|num| h[num.to_i]}
> p players
>
> I didn't exactly understand what you want, so this is just an array of
> the selected values of the "h" hash.

I think OP wants to map numbers to names.  Since keys in this case are
numbers and they are in a relatively small range we can also use an
Array instead a Hash.  But first with a Hash:

h defined as above

irb(main):014:0> input = '1-3-11-7-4-7'
=> "1-3-11-7-4-7"

irb(main):016:0> input.scan(/\d+/).map {|n| h[n.to_i]}
=> ["p1", "p3", "p11", "p7", "p4", "p7"]
irb(main):017:0> input.scan(/\d+/).map {|n| h[Integer(n)]}
=> ["p1", "p3", "p11", "p7", "p4", "p7"]

now with an Array

irb(main):019:0> h=%w{p0 p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 p11}
=> ["p0", "p1", "p2", "p3", "p4", "p5", "p6", "p7", "p8", "p9", "p10", "p11"]
irb(main):020:0> input.scan(/\d+/).map {|n| h[Integer(n)]}
=> ["p1", "p3", "p11", "p7", "p4", "p7"]

Kind regards

robert


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