java - Megaball.java 和 MegaballTest.java

Question

我的 java 作业有问题。我已经为此工作了 2 周，真的需要一些帮助。

问题是:

1. Create a console (standalone) application. This program will allow you to select MegaBall lottery numbers. For the first 5 numbers you will be requested to enter a number that is greater than zero and less than or equal to 56. However, there’s a catch! Each number must be different.

2. When any of the first five numbers is less than 0 or greater than 56 the user will receive a message to this effect and will be asked to reenter the number. You will create the code that will display one message when a number less than 1 is entered and a different message if a number greater than 56 is entered.
   
   If the number is the same as any number entered before it (with the exception of the megaball number) the user will receive a message to this effect and asked to reenter the number. This is the same for the second through fifth numbers. I typed in the same number a couple of times so you will see what occurs when I do.

3. When entering the megaball number, if the number entered IS NOT between 1 and 46 then the user will receive a message to this effect and asked to reenter the number. One message will display if the number is less than 1, and a different if the number is greater than 46.

The following MUST be included in the program:

• You must have multiple classes. One that contains the accessor and mutator methods, a readInput() method and a writeOutput() method. You will not use the mutator methods but include them anyway to show that you know how to write them. Name this first program “Megaball.java”.
• The second program is to be named “MegaballTest.java” and will be responsible for creating a Megaball object and calling the writeOutput() and readInput() methods from the Megaball class.

这是我的解决方案:

import java.util.Scanner;

public class Megaball
{
 Scanner scan = new Scanner(System.in);
 double n1, n2, n3, n4, n5, n6;
 double Num;
 String readInput;
 String writeOutput;

 public Megaball()
 {
  n1 = 0;
  n2 = 0;
  n3 = 0;
  n4 = 0;
  n5 = 0;
  n6 = 0;
 }

 public Megaball(double n1, double n2, double n3, double n4, double n5, double n6)
 {
  this.n1 = n1;
  this.n2 = n2;
  this.n3 = n3;
  this.n4 = n4;
  this.n5 = n5;
  this.n6 = n6;
 }

 public double getNum()
 {
  return Num;
 }

 public void setNum(double n1, double n2, double n3, double n4, double n5, double n6)
 {
  this.Num = Num;
 }

 public String readInput()
 {
  return readInput;
 }

 public String writeOutput()
 {
  return writeOutput;
 }

}




public class MegaballTest
{
 public static void main(String[] args)
 {
  Megaball n1 = new Megaball(0,0,0,0,0,0);
  Megaball n2 = new Megaball(0,0,0,0,0,0);
  Megaball n3 = new Megaball(0,0,0,0,0,0);
  Megaball n4 = new Megaball(0,0,0,0,0,0);
  Megaball n5 = new Megaball(0,0,0,0,0,0);
  Megaball n6 = new Megaball(0,0,0,0,0,0);

 do
 {
 System.out.println("Please enter your 1st number which is between 0 and 56");
 if (n1 < 0 || n1 > 56)
 System.out.println("Number must be between 0 and 56");
 }while (n1 < 0 || n1 > 56);
 System.out.println("Please enter your 2nd number which is between 0 and 56");

}
}

在测试中...我想先确保第一个数字有效，然后再进行其余的操作。这是我不断收到的错误:

G:\MegaballTest.java:15: operator < cannot be applied to Megaball,int
 if (n1 < 0 || n1 > 56)
        ^
G:\MegaballTest.java:15: operator > cannot be applied to Megaball,int
 if (n1 < 0 || n1 > 56)
                  ^
G:\MegaballTest.java:17: operator < cannot be applied to Megaball,int
 }while (n1 < 0 || n1 > 56);
            ^
G:\MegaballTest.java:17: operator > cannot be applied to Megaball,int
 }while (n1 < 0 || n1 > 56);
                      ^
4 errors

Tool completed with exit code 1

非常感谢!!

Answer 1

我认为您正在尝试从用户那里获取输入，然后您希望确保该输入在 0 到 56 之间。目前，您正在检查 Megaball 是否在 0 到 56 之间(您不能这样做，因为 Java 不知道如何比较 Megaball 和 int(因此，你得到的错误)。你实际上需要先在该 do/while 语句中获取用户输入。你想用什么来做那是这样的:

int userInput = scan.next();

获取用户输入的下一个文本。然后您可以运行比较

userInput > -1
userInput < 57

希望这能让您入门。让我们知道进展如何。