Q:

a very simple ques-tion,but i don't know

This is a example of [Introduction to Java Programming(Eighth Edition)]
But when I input on my IDE ,It tell me it's. error
import javax.swing.JOptionPane;
public class DialogBox
{
    public static void main(String[]args)
    {
                 JOptionPaneshowMessageDialog(null,"Hello ");

    }
}

Two error one is swing
the other is second JOptionPane.

A:

Try this and see. Don't forget the .(dot) in JOptionPane.show....
   import javax.swing.JOptionPane;

   public class DialogBox
   {
       public static void main(String[]args)
       {
             JOptionPane.showMessageDialog(null,"Hello ");

       }
   }

