2010/8/23 Ralph Shnelvar <ralphs / dos32.com>:
> Is my understanding correct that === is not a symmetric operator?  ¨Âèáô¬ éî æáãô>  ¨Â ½½> and
>  ¨Â ½½>
> mean different things?

Exactly.

> - - - - -
> irb(main):001:0> class X
> irb(main):002:1> end
> => nil
> irb(main):003:0> x = X.new
> => #<X:0x4d3a660>
> irb(main):004:0> x === X
> => false # this is surprising
> irb(main):005:0> X === x
> => true  this is the test I want ... but was surprised when
> # x === X didn't work.
> irb(main):006:0>
> - - - - -
>
> Does x === X ever mean anything useful?

That depends on what objects x and X refer to.  Remember that X is
only a constant - and not a class or module automatically.

Cheers

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/