Putting controls in arrays?

[Cymro]

Hello all, I couldn't find anything under "control array(s)", so I hope you can answer this for me.

Is it possible to put controls in arrays (ie,

Code:

public static someSortOfDataType[] myArray = {jLabel1,jLabel2,etc};

), and then modify them (myArray[1].setText)? If so, what sort of data type would the array be?

I am aware of a fairly long winded bit of code that creates the controls at runtime (which would be a little annoying to use), but I was wondering if there was another way.

Thanks in advance.

[scuffia]

the easiest way is to declare Object[] array if you have different kinds of controls (if all are JLabel there is no problem ,simply declase JLabel[] ), and each time you need to use a method, you first check if current element is of the class you wish to use like:

Code:

if(myArray[i].getClass().equals(JLabel.getClass()) )
     //do what you want

[Cymro]

Thanks. Before I start doing a test program (tomorrow, as it happens), is there a way of using JLabel[] for existing jLabels, or must they be added at runtime?

[scuffia]

Indeed if you do not know the precise number of JLabels, you can use the java.util.ArrrayList class, which allow you to add an object at runtime, each time you want:

Code:

ArrayList<JLabel> array = new ArrayList<JLabel>();
. . .
array.add(jLabel1);
array.add(jLabel2);
array.add(jLabel3);

Usign this object (google it and you'll find how to use it) you have no problem of what you add runtime or not.

[Cymro]

Thanks very much again, and it seems that I can do that.

However, if I try something like this, attatched to a button:

Code:

 for (int i = 0 ; i < 3 ; i++){
       labRay[i].setText("This label is in the array");
       }

It gives me an error of "Array required, but java.util.ArrayList<javax.swing.JLabel> found". I can't quite comprehend what it's trying to tell me


EDIT: Aha! Got it. I had to use labRay.get(i).setText instead. Thanks again for your help.