From: Patrick He <patrick.he@...>
Date: 2008-10-04T01:29:25+09:00
Subject: Re: Explain this ruby regex

\w* does not match the space between string "one" and "two". it matches
"one", <empty string after "one">, "two", <empty string after "two">.

There are some other examples:

    irb(main):004:0> "one".scan(/^\w*/)
    => ["one"]
    irb(main):005:0> "one".scan(/\w*$/)
    => ["one", ""]


--
Patrick


renton.dan@gmail.com wrote:
> On Oct 3, 11:44 am, Ben Bleything <b...@bleything.net> wrote:
>   
>> On Sat, Oct 04, 2008, renton....@gmail.com wrote:
>>     
>>> "one two".scan(/\w*/).length
>>>       
>>> returns 4. I can see it matching the 2 words and the space, what else
>>> is it matching on? Is there a null terminator, I thought Ruby strings
>>> were not null termed.
>>>       
>> Try replacing #length with #inspect and seeing what the output of scan
>> is.  You'll find that it's returning two empty strings as well.  I
>> suspect what you really want is \w+...
>>
>> Ben
>>     
>
> Yeah, you're right \w+ will pull out the words, which is what I want
> anyway. Though I'm trying to understand what \w* is doing.
> irb(main):015:0> "one two".scan(/\w*/).inspect
> => "[\"one\", \"\", \"two\", \"\"]"
>
> My question is, what is the last "\", where does it come from.
>