From: Nick Bhanji <nickbh@...4u.ca>
Date: 2008-11-08T00:12:27+09:00
Subject: Re: array.equal?

Nick Bhanji wrote:
> Sebastian Hungerecker wrote:
>> Nick Bhanji wrote:
>>> My questions:
>>> 1. why is equal? listed in the methods for the array
>>> 2. what is the definition of equal? in the case of array?
>>> 3. why is there another function eql? performing the actual equal test
>> 
>> 1. Where exactly is it listed? It's not listed in the docs for Array.
>> equal? is defined by Object and it is not overridden for any core class.
>> 2. The same as for anything else: a.equal? b is true if and only if a 
>> and b
>> are actually the same object (i.e. both a and b point to the same 
>> location in
>> memory)
> 
> you are correct to say that equal? is not in the Array docs.  However, 
> when I executed
> a = [1,1]
> a.methods
> 
> equal? method is there on the list of methods supported by the object 
> Array that is used by the variable a.
> 
>> 3. eql? does not perform the "actual equal test" - whatever that is. 
>> eql? is
>> to be used together with hash (and is indeed used that way by Hash, Set 
>> and
> 
> "array.eql?(other) → true or false
> Returns true if array and other are the same object, or are both arrays 
> with the same content. " --- from 
> http://ruby-doc.org/core/classes/Array.html
> 
>> Array#&, Array#| and Array#-).
>> 4. The method that I assume you're looking for is ==
>> 
>> HTH,
>> Sebastian

I did find the reference page that you probably used to explain.  I got 
the reference that explains my imprise definition of equality that you 
were trying to explain.

http://kentreis.wordpress.com/2007/02/08/identity-and-equality-in-ruby-and-smalltalk/

thank you everyone.

Nick.B
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