istream运算符重载>>将不起作用

Question

I have to create an istream operator overload function to read the data the user enters. The function is suppose to read both single chars and single digits while ignoring the chars because only digits are suppose to be entered and printedout. It reads the data coming in but when my they are printed out, it prints out weird symbols instead. i am supplying my istream>> function along with my output<< function although im pretty sure the problem has to be somewhere inside the istream. if anyone can see an error that would be awesome as i've been working on this single problem all day.

    friend ostream& operator<< (ostream& os, const MyInt& x);
friend istream& operator>> (istream& is, MyInt& x);






   ostream& operator<< (ostream& oS, const MyInt& x)    
   {
for (int i = 0; i < x.currentSize; i++)
{
    oS << x.digitList[i];
}
return oS;
   }

    istream& operator>> (istream& is, MyInt& x)
    {
char c;

x.currentSize = 0;
x.maxSize = 5;

c = is.peek();
while(!isdigit(c))
{
    is.ignore();
    c = is.peek();

}

while(isdigit(c))
{
    c =is.get();     

    x.digitList[x.currentSize] = C2I(c);

    x.currentSize++;
    c = is.peek();

    if(x.currentSize >= x.maxSize)
         x.Grow();        
}
return is;

}

Answer 1

Here you are translating ASCII digits to some internal representation:

x.digitList[x.currentSize] = C2I(c);

But there is no translation in the other direction, back to text, when you perform output.