From: Jean-Julien Fleck <jeanjulien.fleck@...>
Date: 2010-07-22T21:41:35+09:00
Subject: Re: Split

2010/7/22 Amir Ebrahimifard <amiref@ymail.com>:
> What is the use of "split"?

Use ri to summon the docs:

~>ri String.split
----------------------------------------------------------- String#split
     str.split(pattern=$;, [limit])   => anArray
------------------------------------------------------------------------
     Divides _str_ into substrings based on a delimiter, returning an
     array of these substrings.

     If _pattern_ is a +String+, then its contents are used as the
     delimiter when splitting _str_. If _pattern_ is a single space,
     _str_ is split on whitespace, with leading whitespace and runs of
     contiguous whitespace characters ignored.

     If _pattern_ is a +Regexp+, _str_ is divided where the pattern
     matches. Whenever the pattern matches a zero-length string, _str_
     is split into individual characters.

     If _pattern_ is omitted, the value of +$;+ is used. If +$;+ is
     +nil+ (which is the default), _str_ is split on whitespace as if `
     ' were specified.

     If the _limit_ parameter is omitted, trailing null fields are
     suppressed. If _limit_ is a positive number, at most that number of
     fields will be returned (if _limit_ is +1+, the entire string is
     returned as the only entry in an array). If negative, there is no
     limit to the number of fields returned, and trailing null fields
     are not suppressed.

        " now's  the time".split        #=> ["now's", "the", "time"]
        " now's  the time".split(' ')   #=> ["now's", "the", "time"]
        " now's  the time".split(/ /)   #=> ["", "now's", "", "the", "time"]
        "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]
        "hello".split(//)               #=> ["h", "e", "l", "l", "o"]
        "hello".split(//, 3)            #=> ["h", "e", "llo"]
        "hi mom".split(%r{\s*})         #=> ["h", "i", "m", "o", "m"]

        "mellow yellow".split("ello")   #=> ["m", "w y", "w"]
        "1,2,,3,4,,".split(',')         #=> ["1", "2", "", "3", "4"]
        "1,2,,3,4,,".split(',', 4)      #=> ["1", "2", "", "3,4,,"]
        "1,2,,3,4,,".split(',', -4)     #=> ["1", "2", "", "3", "4", "", ""]

Cheers,

-- 
JJ Fleck
PCSI1 Lycée Kléber