[jdom-interest] Query regarding the Parent/Child interfaces.

Simon Gauld Simon.Gauld at three.co.uk
Sat Mar 20 02:06:26 PST 2004

Okay, lets put the difference of design behind us with respect to using the
instanceof keyword.

Do Child and Parent provide some much-needed functionality that Element
didn't already?


-----Original Message-----
From: Elliotte Harold - java FAQ
To: Simon Gauld
Cc: jdom-interest at jdom.org
Sent: 19/03/2004 17:53
Subject: RE: [jdom-interest] Query regarding the Parent/Child interfaces.

On Wed, 17 Mar 2004, Simon Gauld wrote:

> Alex: I find it interesting that you believe using instanceof should
> avoided or minimized - this is a technique I find quite useful to be
able to
> derive general functionality - I wasn't aware it was something that
> should be avoided, and am somewhat confused as to why you say minimize
> of it.

In my experience instanceof is a perfomance sink. Any common method that

calls it is almost certainly a hot spot. I go to great lengths to aovid 
it. (Also frequent use of instanceof generally indicates a poorly
set of classes with insufficient use of polymorphism.)

Elliotte Rusty Harold     
elharo at metalab.unc.edu    
elharo at macfaq.com


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