For example

JLabel label0 = new JLabel("");
JLabel label1 = new JLabel("");
JLabel label2 = new JLabel("");
JLabel label3 = new JLabel("");
JLabel label4 = new JLabel("");

for (int i = 0;i<5;i  )
{
    labeli.setText(i);
    
}

In this code, the for automatically change the label texts, first the label0 and after then the label1 etc.. Obviusly, this isn't working. My best solution was I do an if, and if i == 0 set label0 etc.. but maybe there is an easier solution which I don't know. (And if I make 100 elements, it is very long time to write down)

CodePudding user response：

At the simplest of levels, you have a number of objects you want to maintain in an easy/accessible container. Assuming for a second that the list is of a predefined or, after it's initialisation, will never change size without needing to be be re-initialised, an array would be a good choice.

See Arrays for more details.

For example...

import java.awt.EventQueue;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JLabel[] labels = new JLabel[6];

        public TestPane() {
            setLayout(new GridLayout(0, 1));
            for (int index = 0; index < labels.length; index  ) {
                JLabel label = new JLabel(Integer.toString(index));
                // Customise the label, as it' easy to type `label`
                // then `labels[index]` ;)
                add(label);
                labels[index] = label;
            }
        }

    }

}

If, on the other hand, you need something which is more dynamic (can grow and shrink at runtime), then a List of some kind would be more practice, but since you don't seem to understand arrays, maybe you should stick with those first.

CodePudding user response：

1. Create your own class and extend the JLabel class

2. After the initiation of the constructor, add the class into a holder (that holds your custom class)

   class MyJLabel extends JLabel
   {
       public MyJLabel(String name)
       {
           super(name);
           holder.add(this);
       }
   }
   

Your holder should look like

List<MyJLabel> holder = new ArrayList<>();

and then, you can change the text of all your jlabels by using lambda expression:

holder.forEach(jlabel -> jlabel.setText(""));

Note: your variables shouldn't be JLabel but MyJLabel.