Main.java:6: error: package java.swing does not exist
import java.swing.JButton;
^
Main.java:13: error: cannot find symbol
JButton[] numbers = new JButton[9];
^
symbol: class JButton
location: class Ideone
Main.java:13: error: cannot find symbol
JButton[] numbers = new JButton[9];
^
symbol: class JButton
location: class Ideone
Main.java:15: error: cannot find symbol
numbers[i] = new JButton(""+i);
^
symbol: class JButton
location: class Ideone
4 errors