Most languages have only eq and no equal: the == operator in Ruby/Python compares by object reference.

The first statement is startlingly flimsy, and the second is outright false. Equality is rather involved in all three languages.

- Python has address and value comparison (http://docs.python.org/2/reference/expressions.html#is vs http://docs.python.org/2/reference/datamodel.html#object.__e...), but == dispatches to the __eq__ method, so is arbitrarily precise, in principle.

  >>> [1,2,3] is [1,2,3]
  False
  >>> [1,2,3] == [1,2,3]
  True

  irb(main):001:0> class A
  irb(main):002:1> end
  => nil
  irb(main):003:0> a = A.new
  => #<A:0x8f6dd3c>
  irb(main):004:0> a == a
  => true
  irb(main):005:0> a == a.clone
  => false
  irb(main):006:0> x = "abc"
  => "abc"
  irb(main):007:0> x == x
  => true
  irb(main):008:0> x == x.clone
  => true
  irb(main):009:0> (1..10) == 10
  => false
  irb(main):010:0> (1..10) === 10
  => true

  $ perl -le 'print "abc" == "ABC" ? "true" : "false"'
  true
  $ perl -le 'print "abc" eq "ABC" ? "true" : "false"'
  false