今天用java编写了一个租车系统，过程中主要遇到的两个问题：
1、输出数组信息问题：
在得到cars[]数组后，要生成租车信息表，目前有两种思路：一是用循环输出；二是用arrays.tostring()输出数组信息。
用tostring()方法输出数组输出……@……形式的哈希码地址，这里需要对tostring()方法进行重写，在数组涉及到的类中进行重写。
不过用第二种方法输出的其实还是一个数组，形式如图所示。那么问题来了——还有没有更好的输出方法呢？
2、父类方法不能访问子类成员变量：
本来在父类car中写好的getpersoncapacity()和getgoodcapacity()方法似乎不能访问子类中的personcapacity和goodcapacity 这两个成员变量，导致调用参数时始终为0；所以在各子类方法中又独立加上了前面两个方法，问题得以解决。
运行效果图：
代码如下：
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package rentcarsys; /* * 总共有三种车型：载人auto，载货van，载人载货pickup * car 为这三种车型的父类 * 有4种属性： * 编号 = number * 品牌 = brand * 租金/天 = fee * 载人容量 = personcapacity * 载货容量 = goodcapacity */ public class car { int number; string brand; double fee; int personcapacity; double goodcapacity;
public car( int number, string brand, double fee){ //构造方法 this .number = number; this .brand = brand; this .fee = fee; }
public int getnumber(){ return number; }
public string getbrand(){ return brand; }
public double getfee(){ return fee; }
public int getpersoncapacity(){ return personcapacity; }
public double getgoodcapacity(){ return goodcapacity; }
} |
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package rentcarsys; /* * auto为载人汽车，除了car中的属性之外还有载人容量 personcapacity */ public class auto extends car{
private int personcapacity;
public auto( int number, string brand, double fee, int personcapacity) {
super (number, brand, fee); this .personcapacity = personcapacity; }
public int getpersoncapacity() { return personcapacity; }
@override public string tostring() { return number + "\t" + brand + "\t" + fee + "元/天\t" + personcapacity + "人\n" ; }
} |
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package rentcarsys; /* * van为载货汽车，除了car中的属性之外还有载货容量 goodcapacity */ public class van extends car{
private double goodcapacity;
public van( int number, string brand, double fee, double goodcapacity) {
super (number, brand, fee); this .goodcapacity = goodcapacity;
}
public double getgoodcapacity(){ return goodcapacity; }
public string tostring() { return number + "\t" + brand + "\t" + fee + "元/天\t" + goodcapacity + "吨" + "\n" ; }
} |
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package rentcarsys; /* * pickup为载人载货汽车，除了car中的属性之外还有载人容量 personcapacity,载货容量goodcapacity */ public class pickup extends car{
private int personcapacity; private double goodcapacity;
public pickup( int number, string brand, double fee, int personcapacity, double goodcapacity) {
super (number, brand, fee); this .personcapacity = personcapacity; this .goodcapacity = goodcapacity;
}
public int getpersoncapacity() { return personcapacity; }
public double getgoodcapacity(){ return goodcapacity; }
@override public string tostring() { return number + "\t" + brand + "\t" + fee + "元/天\t" + personcapacity + "人\t" + goodcapacity + "吨\n" ; } } |
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package rentcarsys;
import java.util.arrays; import java.util.scanner;
public class login {
public static void main(string[] args){
scanner input = new scanner(system.in); car[] cars = new car[ 6 ];
system.out.print( "欢迎使用答答租车系统：" ); system.out.print( "您是否要租车？1、是 2、否（请输入1或2）" ); int input1 = input.nextint(); if (input1 == 1 ){ system.out.println( "下面是所有车的信息：" );
cars[ 0 ] = new auto( 1 , "奥迪a4" , 500.0 , 4 ); cars[ 1 ] = new auto( 2 , "马自达6" , 400.0 , 4 ); cars[ 2 ] = new pickup( 3 , "皮卡雪6" , 450.0 , 4 , 2 ); cars[ 3 ] = new auto( 4 , "金龙" , 800.0 , 20 ); cars[ 4 ] = new van( 5 , "松花江" , 400.0 , 4 ); cars[ 5 ] = new van( 6 , "依维柯" , 1000.0 , 20 );
system.out.println( "序号\t" + "汽车名称\t" + "租金\t\t" + "容量(载人/载货)" ); system.out.println(arrays.tostring(cars)); // for(int i = 0; i < cars.length; i++){ // system.out.println("编号:"+ (i+1) +" 品牌:"+ cars[i].getbrand() // +" 租金:"+ cars[i].getfee() +"/天 载客量:"+ cars[i].getpersoncapacity()+"人" // +" 载货量:"+ cars[i].getgoodcapacity()+"吨" ); // } } else { system.out.println( "谢谢使用，再见！" ); }
system.out.print( "请输入你要租几种车：" ); int rentnum = input.nextint();
//selected用来保存客户选中了什么车型，以及每种车型的辆数，与car数组是对应关系 int [] selected = new int [ 6 ];
for ( int i = 1 ; i <= rentnum; i++){ system.out.println( "请输入第" + i + "种车型的序号：" ); int nums = input.nextint() - 1 ; system.out.println(cars[nums].getbrand() + "总共需要多少辆：" ); int num = input.nextint(); selected[nums] = num; }
system.out.println( "请输入租车天数：" ); int daysnum = input.nextint();
system.out.println( "您的账单：--------------------------" ); double total = 0 ; for ( int i = 0 ; i < cars.length; i++){ if (selected[i] != 0 ){ system.out.println(selected[i] + "辆" + cars[i].getbrand() + " 总共载客量:" +selected[i]*cars[i].getpersoncapacity()+ "人" + " 总共载货量:" +selected[i]*cars[i].getgoodcapacity()+ "吨" + " " +daysnum+ "天单项费用:" +selected[i]*cars[i].getfee()*daysnum+ "元" ); total += selected[i]*cars[i].getfee()*daysnum; } } system.out.println( "租车总费用：" + total + "元" + "\n" + "欢迎下次光临！------------------------" ); } } |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
原文链接：https://blog.csdn.net/chao2016/article/details/50532660