即使清除，C ++流也会分配0

Question

我正在尝试编写一个程序，该程序输入一个数字和一个数字，并打印该数字包含在数字中的次数。我试图使该程序适用于不合适的用户输入数据，但是当用户输入字符串或单个字符而不是数字时，该变量将获得等于0的赋值。 这是程序的代码：

    #include <iostream>
#include <limits>
using namespace std;
int SafelyInputInteger(long long lowerBound, long long upperBound) // A function which prevents errors caused by inappropriate data input  FOR THE NUMBER
{
    long long intNumber;
    do {
        cout<<"Input a number: "; cin>>intNumber;
        if(cin.fail())
        {
            cin.clear();
            cin.ignore(numeric_limits<streamsize>::max(),'\n');
            continue;
        }
    } while((intNumber<lowerBound)||(intNumber>upperBound));
    return intNumber;
}
int SafelyInputDigit() // A function which prevents errors caused by inappropriate data input  FOR THE DIGIT
{
    int intNumber;
    do {
        cout<<"Input a digit: "; cin>>intNumber;
        if(cin.fail())
        {
            cin.clear();
            cin.ignore(numeric_limits<streamsize>::max(),'\n');
            continue;
        }
    } while((intNumber<0)||(intNumber>9));
    return intNumber;
}
int howManyTimes(long long number, int digit) // A function that counts the times a  given number contains a given digit
{
    int counter=0;
    while(number>0)
    {
        if(digit==number%10) {counter++;}
        number/=10;
    }
    return counter;
}
int main()
{
const long long SMALLESTVALUE=-4294967296; // -4294967296=-2^32
const long long BIGGESTVALUE=4294967295; // 4294967295=2^32-1
long long inputNumber;//The number whose digits we will evaluate
int inputDigit;//The digit that we are going to search for in the number

    inputNumber=SafelyInputInteger(SMALLESTVALUE,BIGGESTVALUE);
    inputDigit=SafelyInputDigit();//Digits are numbers between 0 and 9

    cout<<inputNumber<<" contains "<<inputDigit<<" "<<howManyTimes(inputNumber,inputDigit)<<" times.\n";
 return 0;
}