如何創建一個循環，直到輸入一個哨兵？

Question

我的代碼是猜謎遊戲。當用戶用完猜測或猜測幻數時，我應該問他們是否想再次猜測一個數字。只要用戶不輸入哨兵，它應該能夠運行1000次，這是「否」。我需要讓我的代碼循環到它將繼續前進的位置，直到用戶說「不」爲止。

我試圖在我的代碼的底部要做到這一點，但卡住了，因爲我覺得我應該已經做了一些在一開始，使之成爲環......有人告訴我，我應該怎樣包括這我的代碼？

Answer 1

你需要下面給出通過循環運行：

final String SENTINEL = "no"; 

# put your required code here 

System.out.print(" Would you like to try to guess a number? (Yes or No):"); 
String answer = scan.next(); 

while(!answer.equals(SENTINEL)){ 
    # put your required code here 

    # do all your stuff and then ask users' preference again 
    System.out.print("Would you like to try to guess a number? (Yes or No):"); 
    answer = scan.next(); 
} 

您還可以使用做，而環路，更好地匹配您的需要。

final String SENTINEL = "no"; 
# put your required code here 
System.out.print(" Please enter your name: "); 
String name = scan.next(); 

do{ 
    # put your required code here 

    # do all your stuff and at the end of the loop ask users' preference 
    System.out.print("Would you like to try to guess a number? (Yes or No):"); 
    String answer = scan.next(); 
}while(!answer.equals(SENTINEL)); 

之間的差做-而和而是，DO-而在循環，而不是頂部的底部評估其表達。因此，do塊中的語句總是至少執行一次。