From: Gavin Sinclair <gsinclair@...>
Date: 2004-02-07T15:20:51+09:00
Subject: Re: prepend file line number to array

On Saturday, February 7, 2004, 1:51:56 AM, Joseph wrote:

> [...]

> what i would like to end up with is :

> 1 01/02/2004 bought 100 widgets 19.95 company_1
> 2 01/02/2004 sold 5 widgets 22.95 company_2
> 3 01/02/2004 bought 50 widgets 19.95 company_1


> is there an array method that i can use on each element to prepend the line
> number after reading the file into an array using IO.readlines?  


Sure there is!

  require 'extensions/all'      # extensions.rubyforge.org
  lines = lines.map_with_index { |line, i| "#{i+1} #{line}" }

Although this may be more efficient:

  require 'extensions/all'
  File.open(path) do |f|
    lines = f.map_with_index { |line, i| "#{i+1} #{line}" }
  end

Cheers,
Gavin