lambda表达式——字符串数组按长度排序

代码实现：

package com.lambda;

import java.util.*;
import javax.swing.*;
import javax.swing.Timer;

public class LambdaTest
{
    public static void main(String[] args)
    {
        String[] planets = new String[] { "Mercury", "Venus", "Earth", "Mars",
                "Jupiter", "Saturn", "Uranus", "Neptune" };
        System.out.println(Arrays.toString(planets));
        System.out.println("Sorted in dictionary order:");
        Arrays.sort(planets);
        System.out.println(Arrays.toString(planets));
        System.out.println("Sorted by length:");
        Arrays.sort(planets, (first, second) -> first.length() - second.length());
        System.out.println(Arrays.toString(planets));

        Timer t = new Timer(5000, event ->
                System.out.println("The time is " + new Date()));
        t.start();
        // keep program running until user selects "Ok"
        JOptionPane.showMessageDialog(null, "Quit program?");
        System.exit(0);
    }
}

运行结果：