What does -> mean in JAVA?-javaTutorial-php.cn

This article will introduce to you the meaning of "->" in JAVA. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

What does -> mean in JAVA?

In "JAVA Core Programming", there is a piece of code like this

import javax.swing.*; import java.awt.*; import java.io.File; public class ImageViewer { public static void main(String[] args){ EventQueue.invokeLater(() -> { JFrame frame = new ImageViewerFrame(); frame.setTitle("ImageViewer"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } } class ImageViewerFrame extends JFrame{ private JLabel label; private JFileChooser chooser; private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 400; public ImageViewerFrame(){ setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT); label = new JLabel(); add(label); chooser = new JFileChooser(); chooser.setCurrentDirectory(new File(".")); JMenuBar menuBar = new JMenuBar(); setJMenuBar(menuBar); JMenu menu = new JMenu(); menuBar.add(menu); JMenuItem openItem = new JMenuItem("open"); menu.add(openItem); openItem.addActionListener(Event -> { int result = chooser.showOpenDialog(null); if (result == JFileChooser.APPROVE_OPTION){ String name = chooser.getSelectedFile().getPath(); label.setIcon(new ImageIcon(name)); } }); JMenuItem exitItem = new JMenuItem("exit"); menu.add(exitItem); exitItem.addActionListener(Event -> System.exit(0)); } }

Copy after login

You can see two such codes

() -> { JFrame frame = new ImageViewerFrame(); frame.setTitle("ImageViewer"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }

Copy after login

Event -> { int result = chooser.showOpenDialog(null); if (result == JFileChooser.APPROVE_OPTION){ String name = chooser.getSelectedFile().getPath(); label.setIcon(new ImageIcon(name)); }

Copy after login

Lambda expressions in Java 8. It's an anonymous function.

The above paragraph can be seen as follows:

EventQueue.invokeLater(new Runnable() { public void run() { JFrame frame = new ImageViewerFrame(); frame.setTitle("ImageViewer"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } });

Copy after login

The following paragraph can be seen as:

openItem.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { int result = chooser.showOpenDialog(null); if (result == JFileChooser.APPROVE_OPTION){ String name = chooser.getSelectedFile().getPath(); label.setIcon(new ImageIcon(name)); } } });

Copy after login

It’s just that java automatically translates it for you

Recommended : "java video tutorial"

The above is the detailed content of What does -> mean in JAVA?. For more information, please follow other related articles on the PHP Chinese website!