在一定數量範圍內保留範圍

Question

對於我的Java類，我正在編寫一個小程序，首先選取1到100之間的int數字。然後提示用戶開始猜測正確的int。如果用戶猜測int太高或太低，程序會打印出一個新的範圍供他們猜測。如果用戶輸入String或double，則程序簡單地重新要求用戶輸入int，但不以任何方式改變範圍。

樣品輸出（當保密號20）將如下所示：

 
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! 

節目似乎是幾乎沒有，但有一個例外。其中一個要求是，當用戶鍵入的int超出我們給定的1和100範圍時，打印輸出消息不會改變（如上例所示）。這是我陷入困境的地方，我期待着看有沒有人能幫助我指導正確的答案。

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!"); 
      } 

現在你是不是最小/最大範圍檢查的。您必須爲此添加一個明確的檢查，但是警告（在此處未提供其他答案）是，如果超出範圍，您必須確保不會將輸入處理爲猜測。您當前使用if s的樣式不帶else s意味着您在實施時必須小心。你有幾個選項，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) { 
       // ... 
      } 

，或者用現在的風格堅持，只要你沒有做任何更多的不相關的邏輯迴路（這似乎是在你的程序的情況下）：

  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

當你還希望給用戶提示到原來的最小值和最大值，您應分別保持這兩個值，並在循環的像

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

Answer 3

你開始插入另一個if -check只是檢查相對於祕密號碼的猜測數字。你缺少的是檢查相對於最大值和最小值的猜測數字。例如：

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

Answer 4

在您檢查，如果猜測的數比祕密數量少跌多，把這個檢查之前：

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): "); 
}