數字猜測程序錯誤？

Question

我想創建一個數字猜測程序，用戶輸入一個數字，程序會告訴您輸入是否太高，太低或正確。程序選擇0-100之間的隨機數。問題是，當我開始測試程序時，當我選擇1時，程序告訴我猜測過高。但是這是錯誤的，因爲程序只能做整數。如果用戶輸入的號碼不等於隨機數，則1必須太低。 有人可以看看我的代碼，看看是否有什麼奇怪的。

int guess; 
    int guess2; 
    int guess3; 
    int guess4; 
    int guess5; 
    int random = (int)Math.random() * 100; 
    Scanner input = new Scanner(System.in); 

    System.out.println("Try to guess a number between 0-100. You have five chances."); 
    guess = input.nextInt(); 
    if(guess >= 100 || guess <= 0){ 
     System.out.println("Error, that is not a number between 0-100."); 
    } else if(guess > random){ 
     System.out.println("The guess is too high."); 
    } else if(guess < random){ 
     System.out.println("The guess is too low."); 
    } else if(guess == random){ 
     System.out.println("YOU WIN"); 
    } else{ 
    } 

    System.out.println("Second guess."); 
    guess2 = input.nextInt(); 
    if(guess2 >= 100 || guess2 <= 0){ 
     System.out.println("Error, that is not a number between 0-100."); 
    } else if(guess2 > random){ 
     System.out.println("The guess is too high."); 
    } else if(guess2 < random){ 
     System.out.println("The guess is too low."); 
    } else if(guess2 == random){ 
     System.out.println("YOU WIN"); 
    } else{ 
    } 

    System.out.println("Third guess."); 
    guess3 = input.nextInt(); 
    if(guess3 >= 100 || guess3 <= 0){ 
     System.out.println("Error, that is not a number between 0-100."); 
    } else if(guess3 > random){ 
     System.out.println("The guess is too high."); 
    } else if(guess3 < random){ 
     System.out.println("The guess is too low."); 
    } else if(guess3 == random){ 
     System.out.println("YOU WIN"); 
    } else{ 
    } 

    System.out.println("Fourth guess."); 
    guess4 = input.nextInt(); 
    if(guess4 >= 100 || guess4 <= 0){ 
     System.out.println("Error, that is not a number between 0-100."); 
    } else if(guess4 > random){ 
     System.out.println("The guess is too high."); 
    } else if(guess4 < random){ 
     System.out.println("The guess is too low."); 
    } else if(guess4 == random){ 
     System.out.println("YOU WIN"); 
    } else{ 
    } 

    System.out.println("Last guess."); 
    guess5 = input.nextInt(); 
    if(guess5 >= 100 || guess5 <= 0){ 
     System.out.println("Error, that is not a number between 0-100."); 
    } else if(guess5 > random){ 
     System.out.println("The guess is too high."); 
    } else if(guess5 < random){ 
     System.out.println("The guess is too low."); 
    } else if(guess5 == random){ 
     System.out.println("YOU WIN"); 
    } else{ 
    } 

Answer 1

它看起來不錯，但你需要改變這一行投：

int random = (int)Math.random() * 100; 

到：

int random = (int)(Math.random() * 100); 

目前您的隨機數總是0.爲什麼？因爲您正在將Math.random（）轉換爲int類型，而在Java中則意味着小數點後的所有內容都會丟失。 （因此，0.85將變成0. 0 * 100 = 0）。通過在Math.random（）乘以100之後添加我們施加的括號。

另外，請注意，您的隨機數可能爲0，但永遠不會100. Math.random（）返回一個大於或等於0且小於1的數字。當您將其轉換爲int時，99.9999將變爲99.

如果您希望它真的是0-100 ，你會想要：

int random = (int)(Math.random() * 101); 

另外，你可能希望遊戲在玩家獲勝後終止。因此，改變這種：

System.out.println("YOU WIN"); 

這樣：

System.out.println("YOU WIN"); 
return; //end 

最後，你的空else子句永遠不會被調用。你有條件超出範圍，大於隨機，小於隨機，等於隨機。您可以安全地刪除該死的代碼。

Answer 2

變化int random = (int)Math.random() * 100;到int random = (int)(Math.random() * 100);

Answer 3

有2個主要問題與您的代碼：

首先：

您未能投隨機變量馬上所以隨機值的值始終爲0。

合適的款式是：

int random = (int)(Math.random() * 100); 

二：

你如果結構可怕：

例如：

if(guess >= 100 || guess <= 0){ 

1. 你說猜測是且等於100
2. 你說猜測是少且等於0
3. 您使用||操作數，而不是&&檢查數量在0範圍100

試試這個：

if (guess <= 100 && guess >= 0) { 
     if (guess > random) { 
      System.out.println("The guess is too high."); 
     } else if (guess < random) { 
      System.out.println("The guess is too low."); 
     } else if (guess == random) { 
      System.out.println("YOU WIN"); 
     } 
    } else { 
     System.out.println("Error, that is not a number between 0-100."); 
    } 

說明：如果居興數量爲100和0之間，做以下。如果它不告訴用戶他或她不在該範圍內。

Answer 4

你可以這樣做你的代碼。輕鬆你可以使用for循環

int guess; 
    int random = (int) (Math.random() * 100); 
    Scanner input = new Scanner(System.in); 

    System.out.println("Try to guess a number between 0-100. You have five chances."); 
    for (int i = 0; i < 5; i++) { 
     System.out.println("Chance " + (i + 1)); 
     guess = input.nextInt(); 
     if (guess >= 100 || guess <= 0) { 
      System.out.println("Error, that is not a number between 0-100."); 
     } else if (guess > random) { 
      System.out.println("The guess is too high."); 
     } else if (guess < random) { 
      System.out.println("The guess is too low."); 
     } else if (guess == random) { 
      System.out.println("YOU WIN"); 
      break; 
     } 
    } 
    System.out.println(random);