java - 更新 java 的 arraylist 中的特定记录时出现问题

Question

好吧，我编写了一个程序，将患者的信息存储在数组中，然后要求用户输入患者的 ID，根据该 ID，该特定患者的记录将显示在屏幕上。现在我必须更新用户输入 ID 的患者记录，但我不知道要使用哪个语句以及如何使用它。我相信我可以使用添加和删除，但我不太确定。这是我的计划:-就在 if(up==1) 之后，我在思考该怎么做时遇到了问题。

package samplee.java;

import java.util.*;

public class patient$ {

    public static void main(String[] args) {
        ArrayList<patientss> patient1 = new ArrayList<patientss>();
        Scanner src = new Scanner(System.in);
        Scanner sc = new Scanner(System.in);
        Scanner stc = new Scanner(System.in);
        Scanner sdc = new Scanner(System.in);
        Scanner update = new Scanner(System.in);
        int id, it, num, i;
        String name;
        int ages;
        int id1;
        Boolean leave = false;
        while (!leave) {
            patientss xx = new patientss();
            System.out.println("Enter the patient's ID ");
            System.out.println("-1 to finish entering");
            id = src.nextInt();
            if (id != -1) {
                xx.setId(id);
            }
            System.out.println("Enter the patient's name ");
            System.out.println("-1 to finish entering");
            name = stc.next();
            if (id != -1) {
                xx.setName(name);
                patient1.add(xx);
            }
            System.out.println("Enter the patient's phone number");
            System.out.println("-1 to finish entering");
            num = sdc.nextInt();
            if (id != -1) {
                xx.setNum(num);
                patient1.add(xx);
            } else {
                leave = true;
            }//Escape the while loop.
        }
        System.out.println("Enter the id of a student");
        it = sc.nextInt();
        patientss tt = new patientss();
        for (i = 0; i < patient1.size(); i++) {
            tt = patient1.get(i);
            if (it == tt.getId())
                System.out.println(tt.toString());
            break;
        }
        System.out.println("Enter the id of the student you want to update");
        Scanner id11 = new Scanner(System.in);
        id1 = id11.nextInt();
        int up, id2;
        patientss dd = new patientss();
        for (i = 0; i < patient1.size(); i++) {
            dd = patient1.get(i);
            if (id1 == dd.getId()) {
                System.out.println("If you want to change the name, type 1");
                System.out.println("If you want to change the number, type 2");
                System.out.println("If you want to change the id, type 3");
                up = update.nextInt();
                if (up == 1) {

                }
            }
        }
    }
}

是的，这是我的病人类(class):-

package samplee.java;

public class patientss {
    int id;
    String name;
    int num;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    public String getName() {
        return name;
    }

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String toString() {
        return name + " " + id + " " + num;
    }
}

Answer 1

请考虑使用HashMap<Integer, Patientss>而不是ArrayList<Patientss> 。这样您就可以轻松地通过 ID 查找患者。

HashMap 具有 get 和 put 实现，您可以使用它们来检索和更新对象。