Question

这是我的第一个程序，我遇到了这个问题。我想在用户输入ADD后将内容添加到列表中，在键入REMOVE后从列表中删除并检查当前状态。

我写了这个：

import java.util.*;

public class MainClass {
    public static void main(String[] args) {

        System.out.println("What's your name?");
        Scanner scan = new Scanner(System.in);


        String name;
        name = scan.next();

        System.out.println("Hello " + name);

        ArrayList<String> list = new ArrayList<String>();
        list.add("Ferrari La Ferrari");
        list.add("Lamborghini Huracan");
        list.add("Ducati 1199 Panigale");
        list.add("Porshe 918");
        list.add("McLaren P1");
        list.add("Pagani Zonda F");
        list.add("BMW M3 E92");
        list.add("Audi R8");
        list.add("Peugeot Oxia");
        list.add("Citroen DS 5");


        System.out.print("Now you have " + list.size());
        System.out.println(" cars in the garage.");
        System.out.println("");

        System.out.println("ADD - to add vehicle.");
        System.out.println("REMOVE - to delete vehicle.");
        System.out.println("STATUS - to check current state of slots .");

        String add;
        add = scan.next();

        if (add.equals("ADD")) { 
            System.out.println("Type name of vehicle: ");
            list.add(add);
            add = scan.next();
        }

        while (!add.equals("EXIT")) {
            list.add(add);
            add = scan.next();
        }



        System.out.println(list);

        System.out.println("");
        System.out.print("Currently you have " + list.size());
        System.out.println(" cars in the garage");
        System.out.println("");

        scan.close();

    }
}

我真的不知道如何解决这个问题。

Answer 1

你需要保持ADD，EXIT＆amp;在while循环中使用STATUS（保留，自己编写代码），如下所示

boolean temp =true;
while(temp){
    System.out.println("ADD - to add vehicle.");
    System.out.println("REMOVE - to delete vehicle.");
    System.out.println("STATUS - to check current state of slots .");
    add = scan.next();
    if (add.equals("ADD")) { 
        System.out.println("Type name of vehicle: ");
        add = scan.next();
        list.add(add);

    }
    if(add.equals("EXIT")){
        temp=false;
    }



}

Answer 2

尝试以这种方式实现删除部分。我希望它适合你。

 if (add.equals("REMOVE")){
        System.out.println("You can remove one of the following");
        for (int i= 0; i < list.size(); i++){
          System.out.println(i+1+". "+list.get(i));
            }
        int va = scan.nextInt();
        System.out.println("The car <-"+list.remove(va-1)+"-> was successfully removed");
        System.out.println("Thank you");
    }

Answer 3

检查下面的代码，我已经详细阐述了代码本身的所有重要内容。

在第一个代码块集中，我使用了set collection来存储车辆。

import java.util.*;

public class MainClass {
    public static void main(String[] args) {

        System.out.println("What's your name?");
        Scanner scan = new Scanner(System.in);

        String name;
        name = scan.next();

        System.out.println("Hello " + name);

            HashSet<String> setOfvehicles = new HashSet<String>(); //List will have duplicate values, so if you use set it want have duplicate, Easy to remove
            setOfvehicles.add("Ferrari La Ferrari");
            setOfvehicles.add("Lamborghini Huracan");
            setOfvehicles.add("Ducati 1199 Panigale");
            setOfvehicles.add("Porshe 918");
            setOfvehicles.add("McLaren P1");
            setOfvehicles.add("Pagani Zonda F");
            setOfvehicles.add("BMW M3 E92");
            setOfvehicles.add("Audi R8");
            setOfvehicles.add("Peugeot Oxia");
            setOfvehicles.add("Citroen DS 5");

            System.out.print("Now you have " + setOfvehicles.size());
            System.out.println(" cars in the garage.");
            System.out.println("");

            System.out.println("ADD - to add vehicle."); //Add description
            System.out.println("REMOVE - to delete vehicle."); //REMOVE description
            System.out.println("STATUS - to check current state of slots ."); //STATUS description
            System.out.println("EXIT - to exit.");//EXIT description
            System.out.println("ADD/REMOVE/STATUS/EXIT");//Your system ask ADD/REMOVE/STATUS/EXIT form user
            String userInput = scan.nextLine(); //user first input store here

            while(userInput.compareToIgnoreCase("EXIT") != 0){ //Until user input is EXIT you will ask for input
                if (userInput.compareToIgnoreCase("ADD") == 0) { //If user input is ADD
                    System.out.println("Type name of vehicle: ");//Ask for vehicle name to be add
                    String vehicleName = scan.nextLine();
                    setOfvehicles.add(vehicleName);
                } else if(userInput.compareToIgnoreCase("STATUS") == 0){//If user input is STATUS
                    for(String setOfvehicle :setOfvehicles){
                        System.out.println(setOfvehicle);
                    }
                } else if(userInput.compareToIgnoreCase("REMOVE") == 0){//If user input is REMOVE
                    System.out.println("Type name of vehicle to be removed: ");//Ask for vehicle name to be remove
                    String vehicleName = scan.nextLine();
                    setOfvehicles.remove(vehicleName);
                }
                System.out.println("ADD/REMOVE/STATUS/EXIT");//Your system ask ADD/REMOVE/STATUS/EXIT form user
                userInput = scan.nextLine();//user next input store here
            }

            System.out.println("");
            System.out.print("Currently you have " + setOfvehicles.size());
            System.out.println(" cars in the garage");
            System.out.println("");
            scan.close();
        }
    }

如果您要将车辆存储在列表集合中，则删除此块。

else if(userInput.compareToIgnoreCase("REMOVE") == 0){//If user input is REMOVE
    System.out.println("Type name of vehicle to be removed: ");//Ask for vehicle name to be remove
    String vehicleName = scan.nextLine();
    for(String setOfvehicle :setOfvehicles){
        if(setOfvehicle.equals(setOfvehicle)){
            setOfvehicles.remove(vehicleName);
        }
    }
}

如果您需要更多澄清评论。

用户使用关键字输入ArrayList

3 个答案: