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From Felipe Schnack <feli...@ritterdosreis.br>
Subject RE: instance of (ot)
Date Thu, 20 Feb 2003 19:37:10 GMT
  Hi all!
  Well, what I wanted is Class.isInstance(Object)
  I don't remember who pointed this out, but thank you a lot!!! :-)

On Thu, 2003-02-20 at 16:35, Shapira, Yoav wrote:
> 
> Howdy,
> 
> >  The problem is that I want to test if an object is subclass of a
> >java.lang.Class INSTANCE... Nonsense example:
> 
> Maybe I'm still not understanding ;)  But why doesn't the instanceof
> operator work for you?
> 
> Your example:
> >  java.util.Date date1 = new java.util.Date();
> >  java.sql.Date date2 = new java.sql.Date();
> >  Class clasz = date1.getClass();
> >  if (date2 instanceof clasz)
> >  {
> >      do something...
> >  }
> 
> Why not just do
> if(date2 instanceof date1) ...
> rather than if(date2 instanceof date1.getClass()) ??
> 
> Or are you looking for a comparison that doesn't make subclasses equal?
> For example:
> 
> Set h1 = new LinkedHashSet();
> if(h1 instanceof LinkedHashSet) {
>   // This is true
> }
> 
> if(h1 instanceof HashSet) {
>   // This is true
> }
> 
> if(h1 instanceof Set) { 
>   // This is true
> }
> 
> But you only want the first one?  How about
> 
> Object obj1 = new Object1();
> Object obj2 = new Object2(); // Object2 extends Object1
> 
> if(obj1 instanceof obj1) {
>   // This is false
> }
> 
> if(obj2 instanceof ob1) {
>   // This is true
> }
> 
> if(obj2.getClass().getName().equals(obj1.getClass().getName()) {
>  // This is false -- is this what you want?
> }
> 
> Yoav Shapira
> Millennium ChemInformatics
> 
> 
> 
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-- 

Felipe Schnack
Analista de Sistemas
felipes@ritterdosreis.br
Cel.: (51)91287530
Linux Counter #281893

Centro Universitário Ritter dos Reis
http://www.ritterdosreis.br
ritter@ritterdosreis.br
Fone/Fax.: (51)32303341


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