Tuesday, January 29, 2013

How to change a variables value from a array? (is it even possible?)

This is a little confusing question to express, its probably more Java
then gwt specific, but given that gwt is really javascript, I am not
quite sure what domain it falls under.

ArrayList<Object> fieldList = new ArrayList<Object>();

I then dump a lot of different variables to this array.

fieldList.add(ObjectsURL); //string
fieldList.add(X); //int
fieldList.add(Y); //int
If I change the variable, the values in the array change
too...confirming the array stores a reference to the memory, rather
then value itself.

However, if I then retrieve data from the array then set that...

Object object = ((String)this.fieldList.get(0));

Then set object

object = "meeep!"

ObjectsURL is not set to "meep!" but rather it retains its original

I assume this is because the "object" is not referencing the original
variable anymore, that instead its pointing to a new immutable string
in the memory.
All expected Java behavior I think....but then, how would I go about
setting the actual original variable? is this possible in java? (is it
possible in javascript?). If not, is there an alternative method to
achieve the same thing?

I hope my question explains the problem well enough.

My use-case is trying to make a client only serialization/
deserialization system for a bunch of my objects. I was hoping to put
all the fields into a arraylist I could retrieve for both reading and
writting....thus avoiding having to hard-code long lists of
field[0]=blah and blah=field[0] and then going though constant pains
of needing to renumber them each time I add a new field before

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