猜測遊戲提示詢問太多次

Question

我收到一個錯誤，提示猜測沒有在main中定義。這是怎麼回事？ 編是爲了猜測遊戲

雖然只是因爲在main中定義的猜測而停止，但這使得計算機詢問未經測試的輸入。

#include <cstdlib> 
#include <iostream> 
#include <ctime> 
using namespace std; 

int nextGuess(); 

int main() 
{ 
    srand(time(0)); 
    int number = rand() % 100 + 1; 

    cout <<" --GUESSING GAME-- \n You are to enter numbers, trying to guess rthe computer's number"<< endl; 

int guess = nextGuess(); 
    do 
    {  
    int guess = nextGuess(); 

    if (guess > number) 
     cout <<"Your guess is to high."<< endl; 

    if (guess < number) 
     cout <<"Your guess is too low."<< endl; 

    if (guess == number) 
     cout <<"Good job, that's the number!"<< endl; 
    } 
    while (guess != number); 

    system("pause"); 

} 

int nextGuess() 
{ 
    int guess = 0; 
    cout <<"Please enter a number:"; 
    cin >> guess; 

    return guess; 
} 

** Id粘貼c提示符，但不會複製。

Answer 1

您打電話nextGuess兩次，並在do-while區塊內重新聲明變量guess。更改類似於：

int guess; 
do 
{  
guess = nextGuess(); 

if (guess > number) 
    cout <<"Your guess is to high."<< endl; 

if (guess < number) 
    cout <<"Your guess is too low."<< endl; 

if (guess == number) 
    cout <<"Good job, that's the number!"<< endl; 
} 
while (guess != number); 

Answer 2

使用while{}代替do{}while

int guess = nextGuess(); 
while (guess != number) 
{  
guess = nextGuess(); 

if (guess > number) 
    cout <<"Your guess is to high."<< endl; 

if (guess < number) 
    cout <<"Your guess is too low."<< endl; 

if (guess == number) 
    cout <<"Good job, that's the number!"<< endl; 
} 

Answer 3

你調用nextGuess兩次：一次之前環路，而一旦循環中。刪除第一個呼叫，即循環前的呼叫，但保留變量guess的聲明以外的循環，並且不要再次在循環內聲明它。

Answer 4

在你的while循環中，你正在重新定義變量猜測。它可能改變這樣的事情：

int guess; 
do 
{  
    guess = nextGuess(); 

你現在寫的方式，在循環使用的變量猜測是不是在while條件中使用相同的變量。

Answer 5

這是因爲您要撥打nextGuess兩次。在循環外部聲明變量就足夠了，然後調用它裏面的函數。

#include <cstdlib> 
#include <iostream> 
#include <ctime> 
using namespace std; 

int nextGuess(); 

int main() 
{ 
    srand(time(0)); 
    int number = rand() % 100 + 1; 

    cout <<" --GUESSING GAME-- \n You are to enter numbers, trying to guess rthe computer's number"<< endl; 

    int guess; 

    do{ 
    guess = nextGuess(); 

    if (guess > number) 
     cout <<"Your guess is to high."<< endl; 

    if (guess < number) 
     cout <<"Your guess is too low."<< endl; 

    if (guess == number) 
     cout <<"Good job, that's the number!"<< endl; 
    } 
    while (guess != number); 

    return 0; 
} 
    int nextGuess() 
{ 
    int guess = 0; 
    cout <<"Please enter a number:"; 
    cin >> guess; 

    return guess; 
}