java - 学习Java，For循环不渲染

Question

我在下面创建了这个PassworField方法。目的是如果用户输入正确的密码 hello 则跳出循环。在阻止用户之前，它应该循环 5 次。如果用户第一次输入正确的密码，它确实会爆发，但如果用户第一次输入错误的密码，然后在第二次尝试时更正，则不会爆发。即使我输入正确的密码，它也只会循环 5 次然后阻止。如果您能帮忙，我将不胜感激......让我发疯......

public class LoginPage {


         static String password = "hello";
         static Scanner scn = new Scanner(System.in);
         static String input = scn.nextLine();


        public static void PasswordField() {
            System.out.println("Enter the password");
            for (int i = 0; i <5; i++) {
                if (password.equals(input)) {
                        System.out.println("You are In");
                             break;
                }
                   else if(!input.equals(password)) {
                            System.out.println("Wrong, Please Enter the Password again:");
                            scn.nextLine();
                    }
                else {
                       System.out.println("You are Blocked sucker. call helpdesk");
                }


            }
                            scn.close();
         }

Answer 1

一旦循环终止，您需要检查用户是否超出了允许的最大尝试次数。

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        inputPassword();
    }

    public static void inputPassword() {
        final Scanner scn = new Scanner(System.in);
        final String password = "hello";
        String input;
        int i;
        for (i = 1; i <= 5; i++) {
            System.out.print("Enter the password: ");
            input = scn.nextLine();
            if (password.equals(input)) {
                System.out.println("You are In");
                break;
            } else if (i < 5) {
                System.out.println("Wrong, Please Enter the Password again.");
            }
        }
        if (i > 5) {
            System.out.println("You are blocked as you have exceeded the maximum limit.");
        }
    }
}

示例运行:

Enter the password: 1
Wrong, Please Enter the Password again.
Enter the password: 2
Wrong, Please Enter the Password again.
Enter the password: 3
Wrong, Please Enter the Password again.
Enter the password: 4
Wrong, Please Enter the Password again.
Enter the password: 5
You are blocked as you have exceeded the maximum limit.

另一个示例运行:

Enter the password: 1
Wrong, Please Enter the Password again.
Enter the password: Hello
Wrong, Please Enter the Password again.
Enter the password: hello
You are In

其他一些重要说明:

1. 请勿关闭 System.in 的 Scanner，因为它也会关闭 System.in。
2. 关注Java naming conventions例如根据命名约定，该方法 PasswordField 应命名为 passwordField。