Greenfoot

K_O_P

2012/2/10

#

I've got a problem... I want to copy any object.... So that I've got two Objects of the same class... How can I manage it, without knowing before, which class it is?

sp33dy

2012/2/10

#

If I understand you correctly, you'll need your code to figure out the type and then instantiate a new one. One option is to use instanceOf, i.e:

if (thisObject isInstanceof Class) {
  Class newX = new Class();
}

In the above code, thisObject would be your object variable and Class would be which ever class 'it' might be. The second problem you'll face is making a copy of your first Class. Depending on what type of data you have in it, you may or may not need a 'copy' method rather than just assigning one object into the other. I.E. newX = thisObject will not make a copy but a reference to the first; therefore changing a value in one will be effectively duplicated in the other. It is also possible to use reflection to create the class, but you need to google that; as it is way beyond the normal skill level here (in my opinion).

K_O_P

2012/2/10

#

I know, what you mean! But what I mean is, to to copy an object with all the variables values... and without checking 100 Classes, till I've got it

Busch2207

2012/2/10

#

Mabye try to use an interface class, where is a method, that returns a copy of each Object

public interface Copy
{
    Copy duplicate();
}

and in the classes, that should be able to be copied:

public class Example extends Actor implements Copy
{
    private String ExampleName;
    [...]

    public Copy duplicate()
    {
        Example Exe = new Example();
        Exe.ExampleName = this.ExampleName;
        [...]
        return Exe;
    }
}

And the you can use the "duplicate" - Method, if you have a reference to an Object of the class Copy. For example:

    public Copy getACopyOfTheObject(Copy ObjectToCopy)
    {
        return ObjectToCopy.duplicate();
    }

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