From: Yuri Leikind <YuriLeikind@...>
Date: 2001-09-16T01:18:35+09:00
Subject: [ruby-talk:21209] using my own objects as hash keys - a question

Hello all,

Could someone explain to me why the following 
does not work as I expect:


class MyObject              # will use its objects as hash keys
  def initialize (someAttr)
     @someAttr=someAttr
  end
  
  def hash
     @someAttr.hash
  end

end

key1=MyObject.new('qwerty')
key2=MyObject.new('qwerty')

puts key1.hash == key2.hash #=> true  
# Naturally

hash=Hash.new

hash[key1]=6

puts hash[key1]  #=> 6
# Ok, as expected

puts hash[key2]  #=> nil  
# Why?!!  If key1.hash == key2.hash, why doesn't it work?

# Same question here
puts hash.has_key?(key1) #=> true
puts hash.has_key?(key2) #=> false


Have I missed something ?
I use Ruby 1.6.4

Yuri Leikind