From: Gary Wright <gwtmp01@...>
Date: 2007-02-15T05:22:37+09:00
Subject: Re: Justification for Array#join behaviour?


On Feb 14, 2007, at 2:52 AM, Farrel Lifson wrote:

> What is the justification for [1,2,[3,4]].join(',') being '1,2,3,4'
> instead of '1,2,34'? According to ruby-doc.org join "Returns a string
> created by converting each element of the array to a string, separated
> by sep.". Why should an element be recursively joined if it's also an
> array?

Be aware that Array#to_s has changed in Ruby 1.9

$ irb-1.9
irb(main):001:0> a = [1,2,[3,4]]
=> [1, 2, [3, 4]]
irb(main):002:0> a.to_s
=> "[1, 2, [3, 4]]"
irb(main):003:0> a.join
=> "1234"
irb(main):004:0>

The issue is that Array#to_s defers to Array#inspect in 1.9 instead
of simply concatenating the results of #to_s on all the elements.

I didn't expect this change either and matz pointed me to Array#join

Check out this thread: ruby-talk:220698


Gary Wright