英文:
how to add the objects from main class to ArrayList in other class Java
问题
我有这个类，它应该有3个包含其他类对象的列表。
现在，我该如何使用以下方法从主类中填充列表？
import java.util.ArrayList;import java.util.List;public class FcomCarRentalSystem {public List<Customer> customers = new ArrayList<Customer>();public List<Car> cars = new ArrayList<Car>();public List<Rental> rental = new ArrayList<Rental>();// 添加车辆public String addCar(Car tcar) {cars.add(tcar);String state = "添加车辆成功";return state;}}
注意，Car、Customers、Rental 都是类，它们没有问题。
这是主类。当我添加以下车辆时，应该显示消息"添加成功"。但是在我的主类中没有显示任何内容。
我在这里做错了什么？
public class App {public static void main(String[] args) {FcomCarRentalSystem company = new FcomCarRentalSystem();Car nii1 = new Car("QA33145", "Nissan", CarType.SEDAN, true);company.addCar(nii1);}}
任何帮助将不胜感激。
您可以在这些图片中看到类图中所需的内容。
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英文:
I have this class which is supposed to have 3 lists of objects of other classes.
Now, how can I fill the list from the main class by using the following method
from the class?
import java.util.ArrayList;import java.util.List;public class FcomCarRentalSystem {public List<Customer> customers = new ArrayList<Customer>();public List<Car> cars = new ArrayList<Car>();public List<Rental> rental = new ArrayList<Rental>();// Add Carpublic String addCar(Car tcar) {cars.add(tcar);String state = "“added car successfully”";return state;}
Note that Car, Customers, Rental are classes and they have no problem.
Here is the main class. When I add the following car it is supposed to show the message "added successfully". But nothing shows in my main class.
What did I do wrong here?
public class App {public static void main(String[] args) {FcomCarRentalSystem company = new FcomCarRentalSystem ();Car nii1 = new Car("QA33145","Nissan",CarType.SEDAN,true);company.addCar(nii1);}}
Any help would be appreciated.
You can see in these images what is required with the class diagram.
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答案1
得分: 2
public static void main(String[] args) {FcomCarRentalSystem company = new FcomCarRentalSystem ();System.out.println(company.addCar(new Car()));System.out.println(company.addCustomer(new Customer()));System.out.println(company.addRental(new Rental()));}
英文:
public static void main(String[] args) {FcomCarRentalSystem company = new FcomCarRentalSystem ();System.out.println(company.addCar(new Car()));System.out.println(company.addCustomer(new Customer()));System.out.println(company.addRental(new Rental()));}
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