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class HashSet

Posted on 2002-04-15
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Last Modified: 2010-03-31
I insert some instances of class A to HashSet . When I try to access them with Iterator I get an instance of class Object and not of class A. How can I solve this problem?
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Question by:Afifior
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Expert Comment

by:CEHJ
ID: 6942595
You must cast the result to Class A as in:
ClassA s = (ClassA)iterator.next()
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Jim Cakalic earned 50 total points
ID: 6942600
Did you try simply downcasting the returned objects? Example:

    HashSet hash = new HashSet();
    hash.add(new A());
    Iterator iter = hash.iterator();
    while (iter.hasNext()) {
        A each = (A)iter.next();
    }

Your objects haven't changed type. It is simply that the collections are not type-specific so they accept and return all members as type Object. You can still downcast to the specific type safely -- assuming that your collections are homogeneous.

Best regards,
Jim Cakalic
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LVL 86

Expert Comment

by:CEHJ
ID: 6942655
Hmm. I'm getting a feeling of deja vu!
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