Vererbung (Java)

Programm 1

<code=java>                                                                                                                              </code=java>

<code=java>import javax.swing.*; import java.awt.*; public class myProgram { public static void main(String[] args) { JFrame f = new JFrame("My Window"); JPanel p = new JPanel(); JButton b1 = new JButton("Button 1"); JButton b2 = new JButton("Button 2"); JButton b3 = new JButton("Button 3"); b1.setBackground(new Color(255,0,0)); b3.setBackground(new Color(255,0,0)); p.add(b1); p.add(b2); p.add(b3); f.add(p); f.pack(); f.setVisible(true); } }</code=java>

Programm 2

<code=java>import javax.swing.*; public class myFrame extends JFrame{ myFrame(String name) { super(name); } }                                                                                                                               </code=java>

<code=java>import javax.swing.*; import java.awt.*; public class myProgram { public static void main(String[] args) { myFrame f = new myFrame("My Window"); JPanel p = new JPanel(); JButton b1 = new JButton("Button 1"); JButton b2 = new JButton("Button 2"); JButton b3 = new JButton("Button 3"); b1.setBackground(new Color(255,0,0)); b3.setBackground(new Color(255,0,0)); p.add(b1); p.add(b2); p.add(b3); f.add(p); f.pack(); f.setVisible(true); } }</code=java>

Programm 3

<code=java>import javax.swing.*; import java.awt.*; public class myFrame extends JFrame{ myFrame() { super("My Window"); JPanel p = new JPanel(); JButton b1 = new JButton("Button 1"); JButton b2 = new JButton("Button 2"); JButton b3 = new JButton("Button 3"); b1.setBackground(new Color(255,0,0)); b3.setBackground(new Color(255,0,0)); p.add(b1); p.add(b2); p.add(b3); this.add(p); this.pack(); this.setVisible(true); } }</code=java>

<code=java>public class myProgram { public static void main(String[] args) { myFrame f = new myFrame(); } }                                                                                           </code=java>

Programm 4

<code=java>import javax.swing.*; import java.awt.*; public class myFrame extends JFrame{ myFrame() { super("My Window"); JPanel p = new JPanel(); JButton b1 = new JButton("Button 1"); JButton b2 = new JButton("Button 2"); JButton b3 = new JButton("Button 3"); b1.setBackground(new Color(255,0,0)); b3.setBackground(new Color(255,0,0)); p.add(b1); p.add(b2); p.add(b3); this.add(p); this.pack(); this.setVisible(true); } public static void main(String[] args) { myFrame f = new myFrame(); } }</code=java>

<code=java>                                                                                                                                                           </code=java>

Programm 5

<code=java>import javax.swing.*; import java.awt.*; public class RedButton extends JButton { RedButton(String name) { super(name); this.setBackground(new Color(255,0,0)); } }                                                 </code=java>

<code=java>import javax.swing.*; public class myProgram { public static void main(String[] args) { myFrame f = new myFrame("My Window"); JPanel p = new JPanel(); RedButton b1 = new RedButton("Button 1"); JButton b2 = new JButton("Button 2"); RedButton b3 = new RedButton("Button 3"); p.add(b1); p.add(b2); p.add(b3); f.add(p); f.pack(); f.setVisible(true); } }</code=java>

Programm 6

<code=java>import javax.swing.*; import java.awt.*; public class RedButton extends JButton { RedButton(String name) { super(name); this.setBackground(new Color(255,0,0)); } }                                                                               </code=java>

<code=java>import javax.swing.*; import java.awt.*; public class myFrame extends JFrame{ myFrame() { super("My Window"); JPanel p = new JPanel(); RedButton b1 = new RedButton("Button 1"); JButton b2 = new JButton("Button 2"); RedButton b3 = new RedButton("Button 3"); p.add(b1); p.add(b2); p.add(b3); this.add(p); this.pack(); this.setVisible(true); } public static void main(String[] args) { myFrame f = new myFrame(); } }</code=java>