From: 7stud -- <bbxx789_05ss@...>
Date: 2009-04-27T12:35:21+09:00
Subject: Re: Deleting numbers in array

7stud -- wrote:
> Clayton Lane wrote:
>> David A. Black wrote:
>>> Hi --
>>> 
>>> Clayton Lane wrote:
>>>> I'm new to Ruby and unsure how to delete numbers in an array. I have an
>>>> array filled with numbers from 1 to 100. If I use nums.delete_if {|x| x
>>>> == 9 }, it will delete 9, but I want to remove any number containing 9.
>>>> For example, 19, 39, 92, 99 etc. I tried using a wildcard, but it didn't
>>>> work. I'm sure theres an easy command to do it, but I wasn't able to
>>>> find it on in Ruby documentation. I also want to remove numbers
>>>> containing 0,6,7, and 8 as well. Any help would be greatly appreciated.
>>> 
>>> You're pretty much going to have to convert the numbers to strings. For
>>> example:
>>> 
>>>    array.delete_if {|x| x.to_s[/[06789]/] }
>>> 
>>> 
>>> David
>> 
>> Wow! Ruby is so good! I'm unsure of how to do this final step too. If 
>> any numbers don't contain 1, remove them. Any ideas?
> 
> arr = [51, 52, 20, 36, 79]
> result = arr.delete_if {|x| x.to_s[/[06789]/]}
> p result
> 
> --output:--
> [51, 52]
> 
> result = arr.delete_if do |x|
>   str = x.to_s
>   str[/[02345]/] and not str[/1/]
> end
> p result
> 
> --output:--
> [51]

lol.  I screwed that up!  I guess it was easier for me in C++ than ruby. 
Hmm...for a ruby solution, I find that I have to use the same structure 
as the C++ program:

arr = [51, 52, 22, 20, 36, 79]
result = arr.delete_if {|x| x.to_s[/[06789]/]}
p result

result = arr.delete_if do |x|
  str = x.to_s

  if str[/06789/]
    true #delete
  elsif not str[/1/]
    true #delete
  else
    false #keep
  end

end
p result

--output:--
[51, 52, 22]
[51]

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