有人能告诉我为什么在输入 'y' 继续后我会卡在验证循环中吗？

Question

Why am I getting stuck in my validation loop after hitting Y to continue? I have to use cin.get and can not use strings This program collects input from a user and displays them by using a pointer with an array, I have to validate for negative numbers, letters and newline characters with the appropriate message

#include <iostream>
#include <iomanip>
using namespace std;

void validateUserInput(char *userInputCharArray, int &strLength);

int const ARRAY_SIZE = 100;

int main()
{

    char *userInputCharArray = nullptr;
    char yes = NULL;
    int lengthOfInput;



     //creating a dynamic array size 100
    userInputCharArray = new char[ARRAY_SIZE];

    //loop
    do
    {
        int count = 0; 
        //user prompt and accept input

        cout << "Please enter an integer >= 0 and press <ENTER>: " << endl;
        cin.get(userInputCharArray, ARRAY_SIZE);


        while(userInputCharArray[count] != ' ' && userInputCharArray[count]     != '[=11=]')
        count++;
        {
        if(userInputCharArray[count] == ' ')
            {
                userInputCharArray[count] = '[=11=]';
            }
        }
        lengthOfInput = count;

        validateUserInput(userInputCharArray, lengthOfInput);

        cout << "Your number is: " << endl;
        for(int i = 0; i < lengthOfInput; i++)
        {
            cout << userInputCharArray[i] - '0' << " ";
        }
        cout << endl;

        cout << "Press y to continue or any other button to exit: " <<endl;
        cin >> yes;

        delete [] userInputCharArray;
        userInputCharArray = nullptr;
        userInputCharArray = new char[ARRAY_SIZE];

    }while(yes == 'y' || yes == 'Y');


    cout << "Thank you Good-Bye";
    cout << endl;

    delete [] userInputCharArray;
    userInputCharArray = nullptr;

    system("pause");
    return 0;
}

Im getting stuck in my functions while loop

void validateUserInput(char *userInputCharArray, int &strLength)
{
    int counter = 0;

    while(*userInputCharArray < '0' || (*userInputCharArray >= 'A' &&    *userInputCharArray <= 'Z') 
        || (*userInputCharArray >= 'a' && *userInputCharArray <= 'z') 
        || *userInputCharArray == 0)
    {
        cout << "Please enter a positive integer and press <ENTER>: "    <<endl;
        cin.get(userInputCharArray, ARRAY_SIZE);
    }

    while(userInputCharArray[counter] != ' ' && userInputCharArray[counter]   != '[=12=]')
        counter++;

    if(userInputCharArray[counter] == ' ')
    {
        userInputCharArray[counter] = '[=12=]';
    }
    strLength = counter;
}

Answer 1

根据此处的 while 循环，只要您读入的第一个字符是数字或字母字符，您就会继续调用 in.get。因此，如果您以这些字符之一开始输入，您将永远循环。

我建议您一次输入一行，然后解析您得到的内容。

Answer 2

cin.get(*userInputCharArray);

将只提取一个字符，因此终止字符'\0'不会成为userInputCharArray的一部分。

Answer 3

将其更改为一次读取一行并解析输入。如果您仍然遇到问题，您可以在每次读取之前刷新输入缓冲区，如下所示：

cin.ignore(10, "\n");
cin.get(userInputCharArray, ARRAY_SIZE);

有人能告诉我为什么在输入 'y' 继续后我会卡在验证循环中吗？

Can someone tell me why I am stuck in my validation loop after entering 'y' to continue?

c++

visual-c++

c++11