Question

import csci130.*;

public class Driver {
public static void main(String args[]){

    Encryption pass = new Encryption();

    System.out.println("Please enter a password:");
    String name = KeyboardReader.readLine();

    while (true) {
        if (isValidLength(name)) {
            break;
        }
        System.out.println("Your entered password was not long enough.");
    }
    System.out.println("Encrypted Password:  " + pass.encrypt(name));
    System.out.println("Decrypted Password:  " + pass.decrypt(name));
}
}

boolean isValidLength (String password) {
if (password.length()>minLength)    {
    return true;

}   else    {
    return false;
 }
}

想知道如何让循环工作，如果长度不够长，我可以让用户重新输入长度吗？现在当我编译它时会说密码不够长，但不会让他们重新输入有效的密码。有什么建议吗？

Answer 1

你很亲密。

如果您想要重新要求用户输入密码，如果之前的尝试无效，我会考虑将您的问题和readLine()移到while循环中。

while (true) {
    System.out.println("Please enter a password:");
    String name = KeyboardReader.readLine();
    if (isValidLength(name)) {
        break;
    } else {
        System.out.println("Your entered password was not long enough.");
    }
}

我还做了另一个调整：将“不够长”的消息移到else块中。如果您决定在输入上添加更多验证检查，则此结构将更有意义。

Answer 2

将读取名称的部分移动到循环中：

String name;
while (true) {
    System.out.println("Please enter a password:");
    name = KeyboardReader.readLine();
    if (isValidLength(name)) {
        break;
    }
    System.out.println("Your entered password was not long enough.");
}
System.out.println("Encrypted Password:  " + pass.encrypt(name));
System.out.println("Decrypted Password:  " + pass.decrypt(name));

Answer 3

您需要将readLine（）添加到循环中，以便name变量获取新密码：

while (true) {
    if (isValidLength(name)) {
        break;
    }
    System.out.println("Your entered password was not long enough.");

    System.out.println("Please enter a password:");
    name = KeyboardReader.readLine();
}

循环重新进入

3 个答案: