From: Dave Thomas <Dave@...>
Date: 2001-03-06T23:10:50+09:00
Subject: [ruby-talk:12135] Re: hash.invert loses data if equal values exist - is this the right behaviour?

Tammo Freese <tammo.freese@offis.de> writes:

> By inverting a hash that has same values, I expected to see an Exception.
> Curious which it would be, I tested it and found a surprising result:
> 
> D:\software>ruby -ve 'p [hash = Hash[1, 3, 2, 3], hash.invert]'
> ruby 1.6.2 (2000-12-18) [i386-cygwin]
> [{1=>3, 2=>3}, {3=>2}]
> 
> No exception. Is this correct? 

Any reason why there should be an exception?

  h = { 1 => 2 }	# => {1=>2}
  h[1] = 3 		# => 3
  h                     # => {1=>3}

It isn't exceptional to overwrite a value in a hash with another.


Dave