From: ThoML <micathom@...>
Date: 2008-05-03T03:15:10+09:00
Subject: Re: How to search words starting with a particular char?

> I need to search how many words are starting with a specific character

A word border can be matched with \b.

Using split + grep:
irb(main)> a = 'foo bar foo bar foo bar'
irb(main)> a.split(/\b/).grep(/^f\w*/)
=> ["foo", "foo", "foo"]
irb(main)> a.split(/\b/).grep(/^f\w*/).size
=> 3

Another solution would be to use scan:
irb(main)> a.scan(/\bf\w*/)
=> ["foo", "foo", "foo"]
irb(main)> a.scan(/\bf\w*/).size
=> 3