java - UserId 无法解析为类型错误 java

Question

我对 Java 上的 public void 之类的方法很陌生。

如果有人输入名字:John，姓氏:Smith。我的程序应将 UserID 显示为 jsmith。当我把它全部放在 main 方法中时，一切都工作正常。我希望它们都在同一个类(UserID)上，我还收到一条错误消息，指出插入赋值运算符表达式:

process.userID;

代码如下:

import java.util.Scanner;
public class UserID {

Scanner myScan = new Scanner (System.in);

char firstLetter;
String firstName;
String minCharacters;
String surname; 
String userID;

public void firstName () {
    System.out.print("Please enter your firstname: ");
    firstName = myScan.nextLine();
}

public void surname () {
    System.out.print("Please enter your surname: ");
    surname = myScan.nextLine();
}

public void userID (String userID) {
    firstLetter = firstName.charAt(0);
    minCharacters=surname.substring(0, 5);
    userID = firstLetter+minCharacters;
    System.out.print("User ID = " + userID.toLowerCase());
    System.out.println ("\nPlease keep a note of your User ID");

    myScan.close();
}

public static void main(String[] args) {
    String userID;
    userID process = new UserID();
    process.userID;

}

}

Answer 1

在 Daniel Stanley 的答案之上添加，您不会在主方法中或从命令行获取输入的 userId() 方法中调用 firstname() 和 surname() 方法。