（Java）我不能循环访问我的arraylist对象？

Question

package com.company;

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

public class Main {

    public static void main(String[] args) {
    // write your code here

        Scanner scan = new Scanner(System.in);

        ArrayList<Item> itemList = new ArrayList<>();
        Item item;
        while(true) {
            System.out.println("Name plz?");
            String name = scan.nextLine();
            if (name.isEmpty()) {
                break;
            }

            System.out.println("Education plz?");
            String education = scan.nextLine();
            if (education.isEmpty()) {
                break;
            }

            item = new Item(name, education);
            if (!itemList.contains(item)) {
                itemList.add(item);
            }

        }

        System.out.println("Name & Education: ");
        for(Item detail : itemList) {
            System.out.println(detail);
        }

    }
}

和主类

package com.company;

public class Item {
    String name;
    String education;

    public Item(String name, String education) {
        this.name = name;
        this.education = education;
    }
}

Answer 1

在for循环中，您正在打印detail对象。

for(Item detail : itemList) {
    System.out.println(detail);
}

// prints
com.company.Item@69d9c55

第一部分是包名（认为是文件夹），@后面的随机数是一个对象引用。所以基本上是一个id,用于程序在内存对象中标识创建的对象。

有两种方法可以解决此问题：

public class Item {
    String name;
    String education;

    public Item(String name, String education) {
        this.name = name;
        this.education = education;
    }

    public String getName() {
        return name;
    }

    public String getEducation() {
        return education;
    }
}

// Then in your loop fetch the values
for(Item detail : itemList) {
    System.out.println(detail.getName());
    System.out.println(detail.getEducation());
}

public class Item {
    String name;
    String education;

    public Item(String name, String education) {
        this.name = name;
        this.education = education;
    }

    @Override
    public String toString() {
        return name + ", " + education;
    }
}