Question

我正在尝试执行以下代码，但不断收到此错误：

错误：在ScannerDemo类中找不到主要方法，请将main方法定义为： public static void main(String[] args)

import java.util.Scanner;
class ScannerDemo
public class Main {

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

        System.out.println("Enter a number");
        username = sc.nextLine();
        System.out.println("your number is" + username + "enter your next number");
        username2 = sc.nextline();
        System.out.println("your total is" + username2 );     
    }
}

我认为我必须将Scanner类导入错误，我尝试过不同的方法，但对我来说没有任何效果。

Answer 1

您在顶部连续有两个类声明！这是错的。你的进口很好。尝试：

import java.util.Scanner;
public class ScannerDemo {
  public static void main(String[] args) {
    ...
  }
}

Answer 2

你的班级定义错了。您正尝试定义两个类ScannerDemo和Main。替换：

class ScannerDemo
 public class Main

只有：

public class ScannerDemo

此外，在您的main方法中，您应该引用userName变量，而不是username，并且您没有定义username2。请注意，Java标识符区分大小写：

public static void main (String [] args)
{
  Scanner sc = new Scanner(System.in);
  System.out.println("Enter a number");
  String userName = sc.nextLine();
  System.out.println("your number is" + username + "enter your next number");
  String username2 = sc.nextline();
  System.out.println("your total is" + username2 );
}

Answer 3

import java.util.Scanner;

public class ScannerDemo {

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

        System.out.println("Enter a number");
        username = sc.nextLine();
        System.out.println("your number is" + username + "enter your next number");
        username2 = sc.nextline();
        System.out.println("your total is" + username2 );     
    }
}

Answer 4

if I build the Dockerfile standalone and run the container, it will execute the sql files inside the folder

希望这有帮助

Answer 5

import java.util.Scanner;


public class ScannerDemo {

public static void main (String [] args) {

        Scanner sc = new Scanner(System.in);
        String userName;

        System.out.println("Enter a number");
        int username = sc.nextInt();
        System.out.println("your number is " + username);
        System.out.println("enter your next number");
        int username2 = sc.nextInt();
        System.out.println("your total is " + (username2 + username));     
    }
}

导入扫描仪类的问题

5 个答案: