目录

Eclipse使用

调字体大小

Ptg to JavaBean

解决控制台消失问题

第三题大题

控制台

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Eclipse使用

调字体大小

Window —> Preferences

搜索font

点击Color and Fonts

找到Java

展示字体

这个这个

即可调节字体大小

Ptg to JavaBean

生成 空参构造 带参构造 getter setter方法

Source

解决控制台消失问题

Window -> Show View -> Console

第三题大题

题目

测试类

抽象类 父类 Vechicle

子类 Truck

子类 Bus

全部代码

package Dduo;

public class Prog1 {
	//测试类
	public static void main(String[] args) {
		Vechicle[]arr =new Vechicle[4];
		
		arr[0]=new Truck();
		arr[1]=new Truck("J56789","大众",300,5000);
		arr[2]=new Bus();
		arr[3]=new Bus("J00001","解放",1000,40);

		for(int i=0;i<arr.length;i++) {
			arr[i].show();
			System.out.println(arr[i].rent(10));
		}
	}
}

//抽象类 父类 Vechicle
abstract class Vechicle{
	
	//成员属性
	private String num;
	private String brand;
	private double perRent;
	
	//空参构造 带参构造
	public Vechicle() {
		this.num="JB0000";
		this.brand="红旗";
		this.perRent=0;
	}
	
	public Vechicle(String num,String brand,double perRent) {
		this.num=num;
		this.brand=brand;
		this.perRent=perRent;
	}
	
	//setter getter方法
	public String getNum() {
		return num;
	}
	
	public void setNum(String num) {
		if(num.length()==6) {
			this.num=num;
		}else {
			this.num="JB0000";
		}
	}
	
	public String getBrand() {
		return brand;
	}
	
	public void setBrand(String brand) {
		this.brand=brand;
	}
	
	public double getPerRent() {
		return perRent;
	}
	
	public void setPerRent(double perRent) {
		if(perRent>0) {
			this.perRent=perRent;
		}else {
			this.perRent=0;
		}
	}
	
	//抽象方法 无方法体
	public abstract double rent(int day);
	
	public abstract void show();
	
}
//子类 Truck
class Truck extends Vechicle{
	
	//成员属性
	private double load;
	
	//构造方法
	public Truck() {
		super();
		this.load=10;
	}
	
	public Truck(String num,String brand,double perRent,double load) {
		super(num,brand,perRent);
		this.load=load;
	}
	
	//setter getter方法
	public double getLoad() {
		return load;
	}
	
	public void setLoad(double load) {
		this.load=load;
	}

	//必须重写父类中的抽象方法
	@Override
	public double rent(int day) {
		// TODO Auto-generated method stub
		return getPerRent()*day;
	}

	@Override
	public void show() {
		// TODO Auto-generated method stub
		System.out.print(this.getNum()+","+this.getBrand()+","+this.getPerRent()+","+this.getLoad());
	}
	
}

//子类 Bus
class Bus extends Vechicle{

	private int seat;
	
	//空参构造 带参构造
	public Bus() {
		super();
		this.seat=20;
	}
	
	public Bus(String num,String brand,double perRent,int seat) {
		super(num,brand,perRent);
		this.seat=seat;
	}
	
	//getter setter方法
	public int getSeat() {
		return seat;
	}
	
	public void setSeat(int seat) {
		this.seat=20;
	}
	
	
	//必须重写父类中的抽象方法
	@Override
	public double rent(int day) {
		// TODO Auto-generated method stub
		return getPerRent()*day;
	}

	@Override
	public void show() {
		// TODO Auto-generated method stub
		System.out.print(this.getNum()+","+this.getBrand()+","+this.getPerRent()+","+this.getSeat());
	}
	
}

控制台

最后祝大家考试顺利！