From: "s.ross" <cwdinfo@...>
Date: 2009-08-06T15:04:13+09:00
Subject: Re: remove commas from string

On Aug 5, 2009, at 3:55 AM, Robert Klemme wrote:
> 2009/8/5 Lars Haugseth <njus@larshaugseth.com>:
>> * Jason Lillywhite <jason.lillywhite@gmail.com> wrote:
>>>
>>> I have following string:
>>>
>>> s = "B747-400, 8,357 miles, 561 mph, 4 Pratt & Whitney PW 4056
>>> turbofans, 56,000 lbs."
>>>
>>> I want to remove the comma only from the numbers (8,357 miles and  
>>> 56,000
>>> lbs) separating the thousands. I want the string to read as follows:
>>>
>>> "B747-400, 8357 miles, 561 mph, 4 Pratt & Whitney PW 4056 turbofans,
>>> 56000 lbs."
>>
>> Ruby 1.9 supports look-behind in regular expressions (Ruby 1.8
>> only supports look-ahead):
>>
>>  $ irb1.9
>>
>>  irb(main):001:0> s = "B747-400, 8,357 miles, 561 mph, 56,000 lbs."
>>  => "B747-400, 8,357 miles, 561 mph, 56,000 lbs."
>>
>>  irb(main):002:0> s.gsub(/(?<=\d),(?=\d)/, '')
>>  => "B747-400, 8357 miles, 561 mph, 56000 lbs."
>
> I'r rather do this to be a bit more robust:
>
> irb(main):003:0> s.gsub(/(?<=\d),(?=\d{3})/, '')
> => "B747-400, 8357 miles, 561 mph, 56000 lbs."
>
> Kind regards
>
> robert

Why so complex? Perhaps:

 >> s.gsub(/\b(\d+),(\d+)\b/, '\1\2')
=> "B747-400, 8357 miles, 561 mph, 56000 lbs."

Is there a corner case I'm missing here?