將Scanner對象連接到System.in對象並使用Scanner方法

Question

這是我的問題：

我正在嘗試使用Scanner和System.in從鍵盤獲取輸入並將其分配給int變量。

這就是我所擁有的（完整的程序包含在下面）：

// this program will use scanner objects and system inputs
public class Scanner
{
    public static void main(String[] args)
    {
        int number;  
             // declares integer "number"

        Scanner keyboard = new Scanner(System.in); 
  //-------------------------------------------------------------------
  // declares referance variable (Scanner class) "keyboard", creates       
  // Scanner object that 
  // reads input from System.in, then assigns address of Scanner object 
  // to the reference variable "keyboard"
  //-------------------------------------------------------------------     
        System.out.println("Enter an integer value: ");
             // displays text 
        number = keyboard.nextInt();
            // assigns keyboard input to "number" as integer value

        System.out.println("You entered the integer " + number);
           // displays "number" to see if the program worked
    }
}

當我嘗試使用javac在Windows命令提示符下編譯程序時，出現以下錯誤消息：

error: constructor Scanner in class Scanner
cannot be applied to given types;

Scanner keyboard = new Scanner(System.in);

required: no arguments
found: InputStream
reason: actual and formal argument lists differ in length

error: cannot find symbol
            number = keyboard.nextInt();
                             ^
symbol:   method nextInt()
location: variable keyboard of type Scanner
2 errors

我究竟做錯了什么？

Answer 1

有一個命名沖突 。 從Java語言的角度來看，您必須使Scanner類具有唯一性，可以通過以下兩種方法進行：

1. 重命名課程
   • 改成其他名稱，以便不再有命名沖突

2. 使Scanner類明確

   • 通過使用全限定名

      public static void main(String[] args) { int number; java.util.Scanner keyboard = new java.util.Scanner(System.in); System.out.println("Enter an integer value: "); number = keyboard.nextInt(); System.out.println("You entered the integer " + number); } 

Answer 2

您應該重命名類Scanner-錯誤是，您使用Java標准庫中名稱為Scanner的類。

Answer 3

import java.util.Scanner;  

public class Main {
    public static void main(String[] args){
        int number;
        Scanner keyboard = new Scanner(System.in);

        System.out.println("Enter an integer value: ");

        number = keyboard.nextInt();
        System.out.println("You entered the integer " + number);

    }
}