Java 抽象类和抽象方法

public abstract class Color{
	public void get(){
		
	}
}
class Red extends Color{
	public void get(){
		System.out.println("这是红色");
	}
}

class Blue extends Color{
	public void get(){
		System.out.println("这是蓝色");
	}
}

public class Demo {

	public static void main(String[] args) {
		Color color1 = new Red();
		Color color2 = new Blue();
//		Color color3 = new Color();抽象类不能被实例化
		
		color1.get();
		color2.get();
		
	}
	
}

public abstract class Teacher {
	//含有抽象方法必须是抽象类
	public abstract void Teaching();//只需定义不需实现
}

class Math extends Teacher{         //继承抽象类必须重新实现抽象方法
	public void Teaching(){
	System.out.println("数学老师");	
	}
 }

class English extends Teacher{
	public void Teaching(){
		System.out.println("英语老师");
	}
}

public class Demo {

	public static void main(String[] args) {
		Teacher zhao = new English();
		Teacher yuan = new Math();
		
		zhao.Teaching();
		yuan.Teaching();
		
	}
	
}