父级（这个其实没必要写的）
package com.car;

public class First {
public int number=1;
public String name;
public int money;
public float person;
public float heavy;

}
子级1
package com.car;

public class Num1 extends First {
public int number=1;
public String name="奥迪A4";
public int money=500;
public float person=4f;
public float heavy=0f;
}
子级2
package com.car;

public class Num2 extends First {
public int number=2;
public String name="马自达6";
public int money=400;
public float person=4f;
public float heavy=0f;
};
类推，很简单吧
重要的来了！！！
输出代码
package com.car;
import java.util.Scanner;
public class Test {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Scanner input=new Scanner(System.in);
    System.out.println("***欢迎使用滴滴租车系统***：");
    System.out.println("您是否要租车：1是 0否");
    int kais= input.nextInt(); 
    if(kais==1) {
        System.out.println("您可租车的类型及其价目表：");
        System.out.println("序号     汽车名称     租金                   容量\n 1. 奥迪A4  500元/天  载人：4人\n 2. 马自达6  400元/天  载人：4人\n 3. 皮卡雪6  450元/天  载人：4人\n 4.  金龙           800元/天  载人：20人\n 5. 松花江     400元/天   载货4吨\n 6.  依维柯    1000元/天   载货：20吨");
        Num1 f1=new Num1();
        Num2 f2=new Num2();
        Num3 f3=new Num3();
        Num4 f4=new Num4();
        Num5 f5=new Num5();
        Num6 f6=new Num6();
        int max=0;
        String Mname="";
        float Mperson=0f;
        float Mheavy=0f;
        System.out.println("请输入您要租汽车的数量：");
        int shul=input.nextInt();
        for(int i=1;i<=shul;i++) {
            System.out.println("请输入你要租的第"+i+"辆车序号");
            int xuhao=input.nextInt();
            if(xuhao==1) {  
                max=max+f1.money;
                Mname=Mname+"丶 "+f1.name;
                Mperson=Mperson+f1.person;
                Mheavy=Mheavy+f1.heavy;
            }else if(xuhao==2) {
                max=max+f2.money;
                Mname=Mname+"丶"+f2.name;
                Mperson=Mperson+f2.person;
                Mheavy=Mheavy+f2.heavy;
            }else if(xuhao==3) {
                max=max+f3.money;
                Mname=Mname+"丶"+f3.name;
                Mperson=Mperson+f3.person;
                Mheavy=Mheavy+f3.heavy;
            }else if(xuhao==4) {
                max=max+f4.money;
                Mname=Mname+"丶"+f4.name;
                Mperson=Mperson+f4.person;
                Mheavy=Mheavy+f4.heavy;
            }else if(xuhao==5) {
                max=max+f5.money;
                Mname=Mname+"丶"+f5.name;
                Mperson=Mperson+f5.person;
                Mheavy=Mheavy+f5.heavy;
            }else if(xuhao==6) {
                max=max+f6.money;
                Mname=Mname+"丶"+f6.name;
                Mperson=Mperson+f6.person;
                Mheavy=Mheavy+f6.heavy;
            }else {
                System.out.println("请输入1-6");
                i--;
            }                           
        };
        System.out.println("请输入你要租的天数");
        int day=input.nextInt();
        max=max*day;
        System.out.println("你这次租车有"+Mname+"这几辆车;总共可以座"+Mperson+"个人；总共可以装"+Mheavy+"吨；总金额为"+max+"元");

    }else {
        System.out.println(" see you 凉凉");
    }
}

}