根据迭代次数将字符串用户输入添加到数组列表中

Question

我正在开发一个 Java 项目，并且我的 Super 类具有私有属性。我使用从 Main 中的超类继承的访问器和修改器来设置和获取这些属性。我正在创建一个 for 循环来根据用户的 INT 号遍历输入。我被困在如何获取用户输入的名称并将其添加到循环内的 ArrayList 中，所以完成后我应该有 X 个名称。

        Scanner  input = new Scanner(System.in);
        ArrayList<String> animalList = new ArrayList<String>();
        //local variables
        char     choice;
        int      choice2;
        String   mInputN;
        String   mInputT;
        String   mInputG;
        int      mInputA;
        double   mInputW;
        String   mInputD;

        //user input if else statement for Y or N
        System.out.println("Would you like to add an animal? Y or N ");
        choice = input.next().toUpperCase().charAt(0);
        if (choice == 'Y')  {

            System.out.println("How many animals would you like to add?");
            choice2 = input.nextInt();

            for (i = 0; i < choice2; ++i)  {
                System.out.println("Enter new animal name: ");
                mInputN = input.next();

                System.out.println("Enter type of animal: ");
                mInputT = input.next();

                System.out.println("Enter gender of animal: ");
                mInputG = input.next();

                System.out.println("Enter age of animal: ");
                mInputA = input.nextInt();

                System.out.println("Enter weight of animal: ");
                mInputW = input.nextDouble();

                System.out.println("Date acquired (DD/MM/YYYY");
                mInputD = input.next();

                RescueAnimal animal[i] = new RescueAnimal();
                animal[i].setName(mInputN);
                animal[i].setType(mInputT);
                animal[i].setGender(mInputG);
                animal[i].setAge(mInputA);
                animal[i].setWeight(mInputW);
                animal[i].setAcquisitionDate(mInputD);

                animalList.add(mInputN);

                System.out.println(animal[i].getName() + ", Age: " + animal[i].getAge() + ", Gender: " + animal[i].getGender());
                System.out.print("Type: " + animal[i].getType() + ", ");
                System.out.print("Weight: " + animal[i].getWeight() + ", ");
                System.out.println("Acquisition Date: " + animal[i].getAcquisitionDate());
                System.out.println();

                System.out.println(animalList);
            }

Answer 1

好吧，如果你只是要做System.out.println(animalList);，那么你只会得到一个内存位置，而不是这个列表中的实际内容；所以我个人做的是在用户输入并完成循环之后，将此代码写在第一个 for 循环之外。它是一个for each循环：（删除最后一个System.out.println();）

for(String i : animalList){
System.out.println(i);
}

或者你也可以这样做：

for(int i = 0; i < animalList.length; i++){
System.out.println(animalList[i]);
}

在你打印完动物的信息后：

 System.out.println("Acquisition Date: " + animal[i].getAcquisitionDate() + "\n);

代替：

System.out.println("Acquisition Date: " + animal[i].getAcquisitionDate());
System.out.println();

Answer 2

首先是代码。代码后的解释。

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class RescueAnimal {
    private String name;
    private String type;
    private String gender;
    private int age;
    private double weight;
    private String acquisitionDate;

    public String getName() {
        return name;
    }

    public String getType() {
        return type;
    }

    public String getGender() {
        return gender;
    }

    public int getAge() {
        return age;
    }

    public double getWeight() {
        return weight;
    }

    public String getAcquisitionDate() {
        return acquisitionDate;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setType(String type) {
        this.type = type;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public void setWeight(double weight) {
        this.weight = weight;
    }

    public void setAcquisitionDate(String acquisitionDate) {
        this.acquisitionDate = acquisitionDate;
    }

    public static void main(String[] args) {
        List<RescueAnimal> animalList = new ArrayList<>();
        Scanner input = new Scanner(System.in);
        System.out.println("Would you like to add an animal? Y or N ");
        char choice = input.nextLine().toUpperCase().charAt(0);
        if (choice == 'Y')  {
            System.out.println("How many animals would you like to add?");
            int choice2 = input.nextInt();
            input.nextLine();
            for (int i = 0; i < choice2; ++i)  {
                System.out.println("Enter new animal name: ");
                String mInputN = input.nextLine();

                System.out.println("Enter type of animal: ");
                String mInputT = input.nextLine();

                System.out.println("Enter gender of animal: ");
                String mInputG = input.nextLine();

                System.out.println("Enter age of animal: ");
                int mInputA = input.nextInt();
                input.nextLine();

                System.out.println("Enter weight of animal: ");
                double mInputW = input.nextDouble();
                input.nextLine();

                System.out.println("Date acquired (DD/MM/YYYY");
                String mInputD = input.nextLine();

                RescueAnimal animal = new RescueAnimal();
                animal.setName(mInputN);
                animal.setType(mInputT);
                animal.setGender(mInputG);
                animal.setAge(mInputA);
                animal.setWeight(mInputW);
                animal.setAcquisitionDate(mInputD);

                animalList.add(animal);

                System.out.println(animal.getName() + ", Age: " + animal.getAge() + ", Gender: " + animal.getGender());
                System.out.print("Type: " + animal.getType() + ", ");
                System.out.print("Weight: " + animal.getWeight() + ", ");
                System.out.println("Acquisition Date: " + animal.getAcquisitionDate());
                System.out.println();

                System.out.println(animalList.size());
            }
        }
    }
}

您要创建RescueAnimal 的列表，而不是String 的列表。
你没有声明任何数组，所以你不需要[i]。 ArrayList 不是数组。
您要做的就是根据用户输入的详细信息创建RescueAnimal 的实例，然后将该RescueAnimal 实例添加到您的列表中。