好的，刚才问了一个问题，没有提供我所有的代码，愚蠢的想法。这里是。我正在尝试使用带有字符串的 if 语句来获取成本。无论我做什么，我的成本都会返回为 0。请参阅 CarRental 类，getCost 方法。有人告诉我我可以改变它并使用开关，这很好，但我想了解为什么我正在做的事情无论如何都不起作用，为了知识。
更新：尝试将其更改为开关，结果相同。
import java.util.*;
public class UseCarRental {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Thank you for choosing ICT car Rentals\n"
+ "Pleae enter your full name:");
String renterName = input.nextLine();
System.out.println("Please enter your zip code:");
int renterZipcode = input.nextInt();
input.nextLine();
System.out.println("Please enter the size car you would like:\n"
+ "economy\n"
+ "midsize\n"
+ "fullsize\n"
+ "luxury?");
String carSize = input.next();
System.out.println("How many days do you wish to rent this?");
int rentalDays = input.nextInt();
if (carSize.equals("luxury")) {
System.out.println("Will you be wanting a chauffer (y or n");
String chauffer = input.next();
LuxuryCarRental rentIt = new LuxuryCarRental(renterName,
renterZipcode, carSize, rentalDays,chauffer);
rentIt.display();
} else {
CarRental rentIt = new CarRental(renterName, renterZipcode,
carSize, rentalDays);
rentIt.display();
}
} // end main method
} //end class UseCarRental
class CarRental {
private int days;
private int zip;
private double cost;
private String size;
private double total;
private String name;
CarRental(String renterName, int renterZipcode, String carSize, int rentalDays){
this.days = rentalDays;
this.zip = renterZipcode;
this.name = renterName;
this.size = carSize;
}
double getCost(){
if(size.equals("economy")){
cost = 29.99;
}
if(size.equals("midsize")){
cost = 38.99;
}
if(size.equals("fullsize")){
cost = 43.50;
}
return cost;
}
void display(){
System.out.println("Thank you for using our service.");
System.out.println("Your order is as follows:");
System.out.println("Name: " + name);
System.out.println("Zip code: " + zip);
System.out.println("Car size: " + size);
System.out.println("Cost per day: " + cost);
System.out.println("Days requested: " + days);
total = days * cost;
System.out.println("Total cost: " + total);
System.out.println("If any of the above information is incorrect, too bad bud, because it isn't.");
}
}
class LuxuryCarRental extends CarRental {
private int chauffer = 200;
private int days;
private int zip;
private double cost;
private String size;
private double total;
private String name;
LuxuryCarRental(String renterName, int renterZipcode, String carSize, int rentalDays, String chauffer){
super(renterName, renterZipcode, carSize, rentalDays);
this.days = rentalDays;
this.zip = renterZipcode;
this.name = renterName;
this.size = carSize;
}
@Override
void display(){
System.out.println("Thank you for using our service.");
System.out.println("Your order is as follows:");
System.out.println("Name: " + name);
System.out.println("Zip code: " + zip);
System.out.println("Car size: Luxury");
System.out.println("Cost per day: " + cost);
System.out.println("Days requested: " + days);
System.out.println("Chauffer cost: " + chauffer);
total = days * cost + chauffer;
System.out.println("Total cost: " + total);
System.out.println("If any of the above information is incorrect, too bad bud, because it isn't.");
}
}