Hi, A simple question. What is the correct way of passing&retrieving objects in java? I mean, suppose you want to store a string in an object, and the name to store is passed as a parameter. Problem is, should you store the reference which is passed so that both the "outer" world and the object references the same String? If one stores the reference, a change in to the name in the object will also affect the outer worlds String (it's the same), and the outer-stuff wouldn't notice the change and thinks that the name is the same. Look at the code:

  
  String outer = new String("Outer treats this as constant");
  ...
  method(outer);

class object{
  private String owncopy; 
  
  void method(String param) 
  {
    //alternative one

    owncopy = param;   //DANGER!!

    //alternative two

    owncopy = new String(param);  // Only copy the "stringvalue"

  }
}  

See what I mean? A copy will be safe coz both have their own strings but initially with the same value. If alt 2 is the best/safest way, there seems to be much copying to be done when programming in Java! Any thoughts? /Mankind gave birth to God. Edited by - silvren on September 25, 2001 2:44:50 PM

Thanks for the reply.

But problem remains. String was just an example, it could have been MySpecialObjectThatIWantToChange.

That is, java has no equivalent thing such as "pass param value" which C/C++ does (automatic copying).
Well, java has that, but only for ordinary datatypes (int..).

Any more thoughts?



/Mankind gave birth to God.

Edited by - silvren on September 25, 2001 3:05:10 PM

OK,

Thanks for the reply!
I'll read up on that stuff!

regards

/Mankind gave birth to God.

Edited by - silvren on September 25, 2001 5:09:01 PM