From: Gavin Kistner <gavin@...>
Date: 2005-08-24T23:00:25+09:00
Subject: Re: Novice Q: What's the difference between /\s*/ and /(\s)*/?

On Aug 24, 2005, at 7:47 AM, Gavin Kistner wrote:
> " \t\nHello".match( /^\s*(\w+)/    )  #=>  "Hello" , nil
> " \t\nHello".match( /^(\s)*(\w+)/  )  #=>  "\n"    , "Hello"
> " \t\nHello".match( /^(\s*)(\w+)/  )  #=>  " \t\n" , "Hello"
> "\t   Hello".match( /^\s*(\w+)/    )  #=>  "Hello" , nil
> "\t   Hello".match( /^(\s)*(\w+)/  )  #=>  " "     , "Hello"
> "\t   Hello".match( /^(\s*)(\w+)/  )  #=>  "\t   " , "Hello"
> "\n \tHello".match( /^\s*(\w+)/    )  #=>  "Hello" , nil
> "\n \tHello".match( /^(\s)*(\w+)/  )  #=>  "\t"    , "Hello"
> "\n \tHello".match( /^(\s*)(\w+)/  )  #=>  "\n \t" , "Hello"
>

Three more pertinent data points:

"Hello".match( /^\s*(\w+)/    )  #=>  "Hello" , nil
"Hello".match( /^(\s)*(\w+)/  )  #=>  nil     , "Hello"
"Hello".match( /^(\s*)(\w+)/  )  #=>  ""      , "Hello"