c++ - 字符数组和字数统计

Question

在过去的两个小时里，我一直在尝试不同的方法来防止我在运行该程序时不断遇到的 APPCRASH 错误，但我没有任何运气。基本上，所有这些都是用于作业的简单字数统计程序。它工作正常，直到显示程序运行时发现的字数。此时，它只是卡住了一两秒钟，然后弹出 APPPCRASH 错误，然后关闭。我不知道为什么会这样，有人愿意让我知道我哪里出错了吗？

    int main()
{
    //word counting programs
    char *userInput = new char;
    input(userInput);
    displayResults(wordCount(userInput), userInput);    
    return 0;
}

/***************************************
Definition of function - input         *
prompts the user to input a sentence   *
and stores the sentence into a char    *
array.                                 *
Parameter: char []                     *
****************************************/
void input(char userInput[])
{
    cout << "Enter a sentence (no more than 100 characters) and I will count the words:" << endl;
    cin.getline(userInput, 101);
}

/***************************************
Definition of function - wordCount     *
Accepts the input char array and counts*
the words in the sentence. Returns an  *
int value with the word count.         *
Parameter: char []                     *
Returns: an int with the word count    *
****************************************/
int wordCount(char* userInput)
{
    int count = 0;
    int words = 1;
    if(userInput[0] == '\0')
    {
        words = 0;
    }
    else if(userInput[0] == ' ' || userInput[0] == '\t')
    {
        cout << "Error: can not use a whitespace as the first character!" << endl;
        words = -1;
    }
    else
    {
        while(userInput[count] != '\0')
        {
            if(userInput[count] == ' ')
            {
                words++;
            }
            count++;
        }
    }
    return words;
}

/***************************************
Definition of function - displayResults*
Displays the word count for the user   *
entered input.                         *
****************************************/
void displayResults(int wordCountResult, char userInput[])
{
    if(wordCountResult == -1)
        cout << "Error reading input!" << endl;
    else if(wordCountResult == 0)
        cout << "Nothing was entered." << endl;
    else
    {
        cout << "You entered: " << userInput << endl;
        cout << "That contains " << wordCountResult << " word(s)!" << endl;
    }
}

Answer 1

您正在分配 1 个字节并期望在那里容纳 100 个字节:

char *userInput = new char;

你应该这样写:

char *userInput = new char[101];

更好的是，避免使用原始指针、C 字符串和 new。在 C++ 中使用 std::string。