Groups > comp.lang.java.programmer > #8869

Re: Objects comparaison ?

From	dhtml <dhtmlkitchen@gmail.com>
Newsgroups	comp.lang.javascript, comp.lang.java.programmer
Subject	Re: Objects comparaison ?
Date	2011-10-16 09:05 -0700
Organization	http://groups.google.com
Message-ID	<b2196b98-93ac-49fc-bca5-61ae8fafee24@r2g2000prh.googlegroups.com> (permalink)
References	(6 earlier) <2326223.jLKWLtnpvF@PointedEars.de> <e0b407d3-9663-4c23-9863-5969374eaa2d@e37g2000yqa.googlegroups.com> <2065619.34vx2sxqLb@PointedEars.de> <d66a4e0d-c27d-4fcf-9e1d-74e15613d52a@t38g2000prg.googlegroups.com> <2995463.SPkdTlGXAF@PointedEars.de>

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On Oct 16, 2:41 am, Thomas 'PointedEars' Lahn <PointedE...@web.de>
wrote:
> dhtml wrote:
> > Thomas 'PointedEars' Lahn wrote:
> >> dhtml wrote:
> >> > Thomas 'PointedEars' Lahn wrote:
> >> >> dhtml wrote:
> >> >> > Thomas 'PointedEars' Lahn wrote:
> >> >> >> Jukka K. Korpela wrote:
> >> >> >> > 13.10.2011 22:21, Thomas 'PointedEars' Lahn wrote:
> >> >> >> >> Java's equals() method [– which exists precisely for that
> >> >> >> >> purpose – should provide a good start for an implementation in
> >> >> >> >> ECMAScript.]
>
> >> >> > Java `Object.equals` does nothing more than use Java's == which is
> >> >> > analagous to JavaScript's ===.
>
> >> >> I did not write `Object.equals()', if you cared to notice.
>
> >> > Which Java equals() method did you mean?
>
> >> Context matters.  By "should provide a good *start* for an implementation
> >> *in* ECMAScript" I was referring to the *concept* of Java's
> >> Object.equals() method, a method which is *overriden* by subclasses.
>
> > Not necessarily.
>
> Most definitely it is.  There is String.equals() and, say, Boolean.equals().  
> Both are subclasses of Object and override Object.equals().
>
And there is also java.lang CharSequence and StringBuffer, which do
not. And also:

> > Object `equals` method may be overridden but this is often neglected by
> > programmers. Java guidelines for how to override `equals` are applicable
> > here.
>
> ACK
>
So there really isn't a Java equals method that applies to the OP.
There is Java's guidelines though, to be reflexive, symmetric,
transitive, and consistent. An `equals` method should also have no
observable side effects.
--
Garrett

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Re: Objects comparaison ? dhtml <dhtmlkitchen@gmail.com> - 2011-10-16 09:05 -0700

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