浅谈Java面向对象之内部类

class TalkingClock{
   private int interval;
   private boolean beep;
 
   public TalkingClock(int interval, boolean beep){}
   public void start(){}
 
   public class TimePrinter implements ActionListener{
      public void actionPerformed(ActionEvent event){}
   }
}

OuterClass.this

TalkingClock.this.beep

outerObject.new InnerClass(construction parameters)

OuterClass.InnerClass

public void start(){
      class TimePrinter implements ActionListener{
            public void actionPerformed(ActionEvent event){
                  System.out.println("The time is " + Instant.ofEpochMilli(event.getWhen()));
                  if (beep) {
                        Toolkit.getDefaultToolkit().beep();
                  }
            }
      }
 
      TimePrinter listener = new TimePrinter();
      TalkingClock timer = new Timer(interval, listener);
      timer.start();
} 

public void start(int interval, boolean beep)

new SuperType(construction parameters){
      inner class methods and data
}
 
new InterfaceType(){
      methods and data
}

public void start(){
      var listener = new ActionListener(){
               public void actionPerformed(ActionEvent event){
                  System.out.println("The time is " + Instant.ofEpochMilli(event.getWhen()));
                  if (beep) {
                        Toolkit.getDefaultToolkit().beep();
                  }
               } 
          }
      TalkingClock timer = new Timer(interval, listener);
      timer.start();
} 

class ArrayAlg{
   public static class Pair{
      private double first;
      private double second;
 
      public Pair(double f, double s){
         first = f;
         second = s;
      }
 
      public double getFirst() { return first; }
      public double getSecond() { return second; }
   }
 
   public static Pair minmax(double[] values){
      double min = Double.POSITIVE_INFINITY;
      double max = Double.NEGATIVE_INFINITY;
      for (double v : values){
         if (min > v) min = v;
         if (max < v) max = v;
      }
      return new Pair(min, max);
   }
}