music.java

来自「翁剀JAVA语言那门课程的教案 很多人都看多他的视频教程可惜没有ppt的教案」· Java 代码 · 共 49 行

//: Music.java
// Inheritance & upcasting

class Note {
	private int value;
	private Note(int val) { value = val; };
	public static final Note
		middleC = new Note(0),
		cSharp = new Note(1),
		cFlat = new Note(2);
}

class Instrument {
	public void play(Note n) {
		System.out.println("Instrument.play()");
	}
}

class Wind extends Instrument {
	public void play(Note n) {
		System.out.println("Wind.play()");
	}
}

class Stringed extends Instrument {
	public void play(Note n) {
		System.out.println("Stringed.play()");
	}
}

class Brass extends Instrument {
	public void play(Note n) {
		System.out.println("Brass.play()");
	}
}

public class Music {
	public static void tune(Instrument i) {
		i.play(Note.middleC);
	}
	public static void main(String[] args) {
		Wind flute = new Wind();
		Stringed violin = new Stringed();
		Brass frenchHorn = new Brass();
		tune(flute);
		tune(violin);
		tune(frenchHorn);
	}
}