在一定数量范围内保留范围

Question

对于我的Java类，我正在编写一个小程序，首先选取1到100之间的int数字。然后提示用户开始猜测正确的int。如果用户猜测int太高或太低，程序会打印出一个新的范围供他们猜测。如果用户输入String或double，则程序简单地重新要求用户输入int，但不以任何方式改变范围。

样品输出（当保密号20）将如下所示：

 
c:\csc116> java GuessingGame 
Guess the secret number! 
Enter a number between 1 and 100 (inclusive): 45 
Enter a number between 1 and 44 (inclusive): jlkj 
Enter a number between 1 and 44 (inclusive): 31.0 //double 
Enter a number between 1 and 44 (inclusive): 1000 //outside the range of 1-100 
Enter a number between 1 and 44 (inclusive): 34 
Enter a number between 1 and 33 (inclusive): 15 
Enter a number between 16 and 33 (inclusive): 20  
You win! 

节目似乎是几乎没有，但有一个例外。其中一个要求是，当用户键入的int超出我们给定的1和100范围时，打印输出消息不会改变（如上例所示）。这是我陷入困境的地方，我期待着看有没有人能帮助我指导正确的答案。

import java.util.*; 


public class GuessingGame { 


    public static void main(String[] args) { 
     introduction(); 
     Scanner console = new Scanner(System.in); 
     Random rand = new Random(); 

     int guess = 0; 
     int minimum = 1; 
     int maximum = 100; 
     int secretNumber = rand.nextInt(100) + 1; 

     System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
     while (guess != secretNumber) { 
      if (console.hasNextInt()) { 
       guess = console.nextInt(); 
       if (guess > secretNumber) { 
        maximum = guess - 1; 
        System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
       } 
       if (guess < secretNumber) { 
        minimum =guess + 1; 
        System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
       } 
       if (guess == secretNumber) { 
        System.out.println("You win!"); 
       } 
      } else { 
       console.next(); 
       System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
      } 
     } 
    } 


    public static void introduction() { 
     System.out.println("Guess the secret number!"); 
    } 
} 

Answer 1

您有：

  guess = console.nextInt(); 
      if (guess > secretNumber) { 
       maximum = guess - 1; 
       System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
      } 
      if (guess < secretNumber) { 
       minimum =guess + 1; 
       System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
      } 
      if (guess == secretNumber) { 
       System.out.println("You win!"); 
      } 

现在你是不是最小/最大范围检查的。您必须为此添加一个明确的检查，但是警告（在此处未提供其他答案）是，如果超出范围，您必须确保不会将输入处理为猜测。您当前使用if s的样式不带else s意味着您在实施时必须小心。你有几个选项，如：

  guess = console.nextInt(); 
      if (guess < minimumAllowed || guess > maximumAllowed) { 
       // handle error 
      } else { 
       // handle valid input 
       if (guess > secretNumber) {   
        // ... 
       } 
       if (guess < secretNumber) { 
        // ... 
       } 
       if (guess == secretNumber) { 
        // ... 
       } 
      } 

或者：

  guess = console.nextInt(); 
      if (guess < minimumAllowed || guess > maximumAllowed) { 
       // handle error 
      } else if (guess > secretNumber) {   
       // ... 
      } else if (guess < secretNumber) { 
       // ... 
      } else if (guess == secretNumber) { 
       // ... 
      } 

，或者用现在的风格坚持，只要你没有做任何更多的不相关的逻辑回路（这似乎是在你的程序的情况下）：

  guess = console.nextInt(); 
      if (guess < minimumAllowed || guess > maximumAllowed) { 
       // handle error 
       continue; 
      } 
      // handle valid input 
      if (guess > secretNumber) {   
       // ... 
      } 
      if (guess < secretNumber) { 
       // ... 
      } 
      if (guess == secretNumber) { 
       // ... 
      } 

Answer 2

当你还希望给用户提示到原来的最小值和最大值，您应分别保持这两个值，并在循环的像

guess = console.nextInt(); 
if (guess > originalMaximum) { 
    System.out.print("Enter a number less then " + originalMaximum); 
} 

Answer 3

你开始插入另一个if -check只是检查相对于秘密号码的猜测数字。你缺少的是检查相对于最大值和最小值的猜测数字。例如：

if (guess > maximum) { 
    System.out.print("Too high!"); 
} else if (guess < minimum) { 
    System.out.print("Too low!"); 
} 

Answer 4

在您检查，如果猜测的数比秘密数量少跌多，把这个检查之前：

if (guess < minimum || guess > maximum) 
{ 
    System.out.print("Please enter a number between " + minimum + " and " + maximum); 
    continue; 
} 

if (guess > secretNumber) 
{ 
    maximum = guess - 1; 
    System.out.print("Enter a number between " + minimum + " and " + maximum + " (inclusive): "); 
}