Question

package homework4;
import java.util.Scanner;
public class Prog4 {
static Scanner scanner = new Scanner(System.in);
public static void main(String[] args)
{   CreditCardNumber[] cred1;
    CreditCardNumber cred2 = getInput();
    Display("The complete number from your input:", cred2);
    cred1 = getInputArray();
    DisplayArray(cred1);
    TryAnother(cred1);
}

public static CreditCardNumber getInput() {
    String ID;
    String accNum;
    CreditCardNumber tempCred;      
    System.out.printf("Please enter issuer ID:");
    ID = scanner.next();
    System.out.printf("Please enter account number:");
    accNum = scanner.next();
    tempCred = new CreditCardNumber(ID, accNum);

    return tempCred;
}
public static void Display(String ch, CreditCardNumber cred2)
{

    System.out.println(ch);
    System.out.println(cred2.toString().replaceAll(".{4}", "$0   "));       
}

public static CreditCardNumber[] getInputArray()
{
    CreditCardNumber[] tempArray;
    String tempID;
    int size;       
    System.out.printf("Please enter size of the aray:");
    size = scanner.nextInt();
    if(size < 1)
    {
        size = 1;
    }
    tempArray = new CreditCardNumber[size];
    System.out.printf("Please enter issuer ID:");
    tempID = scanner.next();
    for(int i = 0; i < tempArray.length; i++)
    {
        tempArray[i] = new CreditCardNumber();
        tempArray[i].CreateCred(tempID);
    }

    return tempArray;
}

public static void DisplayArray(CreditCardNumber[] cred1)
{
    for(int i = 0; i< cred1.length; i++)
    {
        Display("Credit Card # " + i+":" + '\n', cred1[i]);
    }
    System.out.println();
}

public static boolean TryAnother(CreditCardNumber[] cred1)   
{
    String s;
    System.out.printf("Get more credit card numbers? (n for no):");
    s = scanner.next();
    while(s.charAt(0) != 'N' && s.charAt(0) != 'n')
    {                                       
            cred1 = getInputArray();
            DisplayArray(cred1);    
            if(s.charAt(0) != 'N' && s.charAt(0) != 'n')
            TryAnother(cred1);
    }       


    return false;   
}
}

嗨我有一个Tryanother方法的问题，当我回答没有进程没有终止但反而提示用户再次进入数组的大小：

Please enter issuer ID:321321
Please enter account number:654654654
The complete number from your input:
3213   2165   4654   6549   
Please enter size of the aray:7
Please enter issuer ID:789789
Credit Card # 0:

7897   8987   8895   1653   
Credit Card # 1:

7897   8935   5880   5197   
Credit Card # 2:

7897   8997   8152   8134   
Credit Card # 3:

7897   8996   1605   8067   
Credit Card # 4:

7897   8953   2006   5521   
Credit Card # 5:

7897   8964   3319   8191   
Credit Card # 6:

7897   8986   1830   7068   

Get more credit card numbers? (n for no):y
Please enter size of the aray:3
Please enter issuer ID:345345
Credit Card # 0:

3453   4590   2392   9734   
Credit Card # 1:

3453   4549   5025   1905   
Credit Card # 2:

3453   4504   2989   0927   

Get more credit card numbers? (n for no):n
Please enter size of the aray:

正如你可以看到当我输入'y'程序时，它会提示用户输入数组的大小，但是当我输入'n'而不是终止程序提示用户输入数组的大小

我该如何解决这个问题？

提前谢谢

Answer 1

注意到你的while循环中有s.charAt(0) != 'N' && s.charAt(0) != 'n'，并且在循环中递归调用相同的函数。

将其更改为if(s.charAt(0) != 'N' && s.charAt(0) != 'n')

Answer 2

使用String.startsWith（）方法。

while(!s.startsWith("n") && !s.startsWith("N"))

但它仍然适用于你的方法，我正在仔细研究它。：）

输入no时，进程不会终止

2 个答案: