From: Dave Thomas <Dave@...>
Date: 2001-04-25T04:10:40+09:00
Subject: [ruby-talk:14169] Re: Ruby way to delete entries from an array

Jim Freeze <jim@freeze.org> writes:

> I have an array where I need to delete several entries.
> Here is how I am doing it.
> 
> a = ["cat\n", "dog\n", "bird \n"]
> rm = ["cat", "bird"]
> 
> rm.each do |del|
>   for i in (0...a.size).collect.reverse
>     a.delete_at(i) if /#{del}/ =~ a[i]
>   end
> end
> 
> Is there a more compact way to do this?


Well, this is more compact. The fact that you're using regexp matches
makes it a little tricky.

 pattern = Regexp.new(rm.join('|'))
 a.delete_if {|entry| entry =~ pattern }

In the general case, where the elements of 'rm' might contain meta
characters, you'd need the somewhat more cumbersome:

 pattern = Regexp.new(rm.collect {|str| Regexp.escape(str) } .join('|'))


Regards


Dave