面向对象第四章课后习题

1.设计Bird,Fish类，都继承自抽象类Animal,实现其抽象方法info(),并输出他们呢的信息。

package exercises8;

public abstract class Animal {
	private int age; //父类的共同属性，年龄

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}
	public abstract void info () ;//父类抽象方法
		
}
package exercises8;

public class Bird extends Animal {
	private String colour;//子类自己的属性（颜色）

	public String getColour() {
		return colour;
	}

	public void setColour(String colour) {
		this.colour = colour;
	}
	public  void info () {
		System.out.println("我是一只"+getColour()+"的鸟!");
		System.out.println("今年"+super.getAge()+"岁了！");
	}
}
package exercises8;

public class Fish extends Animal {
	private int catty;//子类自己的属性

	public int getCatty() {
		return catty;
	}

	public void setCatty(int catty) {
		this.catty = catty;
	}
	public void info() {
		System.out.println("我是一只"+getCatty()+"斤重的鱼！");
		System.out.println("今年"+super.getAge()+"岁了！");
	}
}
package exercises8;

public class Test {

	public static void main(String[] args) {
		Bird bi = new Bird();
		bi.setColour("红色");
		bi.setAge(4);
		bi.info();
		System.out.println();
		Fish fi = new Fish();
		fi.setCatty(5);
		fi.setAge(2);
		fi.info();
	}

}

2.兜兜家养了两只家禽：一只鸡和一只鸭。请用面向对象思想的封装，继承的特性进行描述。

package exercises9;

public abstract class Poultry {
	private String name;//共同属性名字
	private String hobby;//共同属性爱好
	private String action;//共同属性的行为
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getHobby() {
		return hobby;
	}
	public void setHobby(String hobby) {
		this.hobby = hobby;
	}
	public String getAction() {
		return action;
	}
	public void setAction(String action) {
		this.action = action;
	}
	public abstract void print();//父类抽象方法 
}
package exercises9;

public class Chicken extends Poultry {
	public void print() {
		super.setName("喔喔");
		System.out.println("我叫"+super.getName()+"是一只芦花鸡！");
		super.setHobby("吃虫子!");
		System.out.println("我喜欢"+super.getHobby());
		super.setAction("打鸣!");
		System.out.println("我会"+super.getAction());
	}
}
package exercises9;

public class Duck extends Poultry {
	public void print() {
		super.setName("嘎嘎");
		System.out.println("我叫"+super.getName()+"是一只斑嘴鸭！");
		super.setHobby("吃小鱼虾!");
		System.out.println("我喜欢"+super.getHobby());
		super.setAction("游泳!");
		System.out.println("我会"+super.getAction());
	}
}package exercises9;

public class Test {

	public static void main(String[] args) {
		Chicken ch = new Chicken();
		ch.print();
		System.out.println();
		Duck du = new Duck();
		du.print();

	}

}