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Referencing a public variable...

Nick Davies
Greenhorn

Joined: Apr 22, 2005
Posts: 3
Hi there, I have a rather silly question, however its got the better of me!

This is simple example of the work I'm doing:

I have a variable:

public String varname;

and it stores some text.

How do i reference that variable in another form? For example, I have a label in a seperate form.

JLabel mylabel = new JLabel();

How do I get it to display the text from the variable (varname) in the other form

mylabel.setText(varname);

^^ This doesn't work. How do i reference the variable correctly?

Help much appreciated
Nick
marc weber
Sheriff

Joined: Aug 31, 2004
Posts: 11343

When you say, "in a separate form," I'm assuming this means in a different class. If so, you'll need to reference an instance of the class containing the variable. For example...

mylabel.setText(myInstance.varname);

...where "myInstance" is an instance of the class in which varname is defined.

(Otherwise, please post the error message you're getting.)


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Nick Davies
Greenhorn

Joined: Apr 22, 2005
Posts: 3
Thanks for your reply. Yeah sorry, i meant a seperate class not form.

The error it gives me is:



Any suggestions?

Nick
marc weber
Sheriff

Joined: Aug 31, 2004
Posts: 11343

It appears that the variable is actually within scope. The problem is that you're trying to access an instance variable from a static context (probably a main method).

Basically, the solution is the same: You need to use a reference to an instance that contains the variable.
Ben Souther
Sheriff

Joined: Dec 11, 2004
Posts: 13410

You could also declare the public variable to be static:

Of course if you do this, all instances of SomeClass.varName will be pointing to the same String object.
[ April 27, 2005: Message edited by: Ben Souther ]

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