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java - 使用计数器向数组添加值

问题描述

在过去的 1.5 个月里，我一直在学习 java。现在，讲师要求我们创建一个程序，该程序从用户那里获取姓名和电话号码（但在一种方法中），直到用户输入“E”。然后程序应该打印存储在所有数组中的所有信息。

该程序有一个主菜单，用户将输入“1”来创建一个帐户（姓名和电话号码），然后主菜单再次出现，用户创建另一个帐户等等......直到他选择另一个菜单中的选项或输入“E”以存在并打印所有帐户的摘要。

我的问题是我试图创建一个计数器作为对数组中每个帐户点的引用（数组中的索引）；因此，每次用户输入名称和数字后，计数器加 1，数组索引加 1 并移动到下一个位置……但这不起作用。

代码没写完，停在选择1测试create account方法

    public static void addDonor(String[] a1, String[] a2, char[] a3, int[] a4, int [] a5){
    Scanner input = new Scanner(System.in);


    System.out.print("  Enter the name (first and last):" + " ");
    String name = input.nextLine();
    System.out.print("  Enter Mobile No.:" + " ");
    String phone = input.next();

    if (phone.length() < 10 && phone.startsWith("0") == false){
        while (true){
            System.out.println("Wrong Mobile NO... try again!");
            System.out.print("  Enter Mobile No.:" + " ");
            phone = input.next();
            if (phone.length() > 10 || phone.startsWith("0") == true)
                break;
        }
    }

    System.out.print("  Enter Blood Group Type (A, B or O):" + " ");
    char blood =  input.next().charAt(0);

        while (blood != 'a' || blood != 'b' || blood != 'c'){
            System.out.println("Wrong Blood Group Type... try again!");
            System.out.println("    Enter Blood Group Type (A, B or O):" + " ");
            blood =  input.next().charAt(0);
            if (blood == 'A' || blood == 'B' || blood == 'O')
                break;    
        }
        int counter = 0;
        a1[counter] = name;
        a2[counter] = phone;
        a3[counter] = blood;
        a4[counter] = 1;
        a5[counter] = 1;
        counter++;

}

    public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

        String[] Name = new String[20];
        String[] Mobile = new String[20];
        char[] Blood_Gp = new char[20];
        int[] Count_o_Donation = new int[20];
        int[] Blood_Stock = new int[20];



        while (true){
            displayMainMenu();
        readAndVerify();
        String choice = readAndVerify();

            switch (choice){
                case "1":
                    addDonor(Name, Mobile, Blood_Gp, Count_o_Donation, Blood_Stock);
                    break;
            }
           if (choice.equals("e")) 
               break;
        }


        System.out.println(Name[0]);
        System.out.println(Name[1]);



}

标签： javaarrays

解决方案

问题是您正在 addDonor 方法中创建变量索引。因此，每次调用该方法时，都会创建一个值为 0 的新变量，这就是它不移动的原因。您应该在方法外部创建变量并将其作为参数传递。

像这样的东西：

public static void main(String[] args) {
Scanner input = new Scanner(System.in);

    String[] Name = new String[20];
    String[] Mobile = new String[20];
    char[] Blood_Gp = new char[20];
    int[] Count_o_Donation = new int[20];
    int[] Blood_Stock = new int[20];
    int index = 0;

    while (true){
        displayMainMenu();
    readAndVerify();
    String choice = readAndVerify();

        switch (choice){
            case "1":
                addDonor(Name, Mobile, Blood_Gp, Count_o_Donation, Blood_Stock, index);
                index++
                break;
        }
       if (choice.equals("e")) 
           break;
    }


    System.out.println(Name[0]);
    System.out.println(Name[1]);

}

   public static void addDonor(String[] a1, String[] a2, char[] a3, int[] a4, int [] a5), int index{
Scanner input = new Scanner(System.in);


System.out.print("  Enter the name (first and last):" + " ");
String name = input.nextLine();
System.out.print("  Enter Mobile No.:" + " ");
String phone = input.next();

if (phone.length() < 10 && phone.startsWith("0") == false){
    while (true){
        System.out.println("Wrong Mobile NO... try again!");
        System.out.print("  Enter Mobile No.:" + " ");
        phone = input.next();
        if (phone.length() > 10 || phone.startsWith("0") == true)
            break;
    }
}

System.out.print("  Enter Blood Group Type (A, B or O):" + " ");
char blood =  input.next().charAt(0);

    while (blood != 'a' || blood != 'b' || blood != 'c'){
        System.out.println("Wrong Blood Group Type... try again!");
        System.out.println("    Enter Blood Group Type (A, B or O):" + " ");
        blood =  input.next().charAt(0);
        if (blood == 'A' || blood == 'B' || blood == 'O')
            break;    
    }

    a1[index] = name;
    a2[index] = phone;
    a3[index] = blood;
    a4[index] = 1;
    a5[index] = 1;

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