From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2013-02-08T17:57:02+09:00
Subject: Re: #split vs. #length. Different returns.

On Fri, Feb 8, 2013 at 7:48 AM, Tom Stut <lists@ruby-forum.com> wrote:
> I am wondering why these two lines of code at the bottom, which seem to
> say the same thing, produce different results.
>
> text is simply a long string.
>
> words = text.scan(/\w+/)
>
> stop_words = %w{the a by on for of are with just but and to the my I has
> some in}
> key_words = text.split{/\w../}.select{|word| !stop_words.include?(word)}
>
> # This line of code results in a higher percentrage of key words to stop
> words 76.58%
> key_words_to_stop_words = ((key_words.length.to_f /
> text.split{/\w../}.count.to_f) * 100)
> # This line has been rendered as a comment, but produces 75.13% when run
> through ruby
> # key_words_to_stop_words = ((key_words.length.to_f/ words.length.to_f)
> * 100)
>
> puts "#{key_words_to_stop_words} % of key words."

String#split doesn't receive a block to specify where to split. So

text.split {/\w../} is the same as text.split, which splits the text
by whitespace.

1.9.2p290 :008 > text = "one, two.three four five"
 => "one, two.three four five"
1.9.2p290 :009 > text.scan(/\w+/)
 => ["one", "two", "three", "four", "five"]
1.9.2p290 :010 > text.split
 => ["one,", "two.three", "four", "five"]


Jesus.