brad wrote:
> In the example below, possible_number is a string of one or more
> digit(s). For example, it may be 4 or 4444. However, when I attempt to
> perform the times 2 calculation, the ASCII value of 4 (which is 52) is
> used instead of 4 itself. I need to be able to easily reverse the
> order of the digits and to only perform this calculation on even
> positioned digits... that's why I'm using string instead of int. Any
> suggestions on how to make 4*2 = 8 I've tried atoi() type casting,
> etc. I'm stuck. Still learning c++.
>
> Thanks for any help!
>
> int position = 0;
>
> string::reverse_iterator rit;
> for (rit=possible_number.rbegin(); rit < possible_number.rend();
> rit++) {
First off, try using more of ++rit, it's better than rit++.
> if (position % 2 == 0)
> {
> // Here's the problem *rit * 2 = 104, not 8
> cout << position << *rit * 2 << endl;
An element of a string is of type 'char'. As you have found out
already, the value is controlled by the encoding of the symbol.
If you want to convert a char that supposedly contains a decimal
digit into its corresponding number, you need to (a) test to see
that it's actually a digit (see 'isdigit' function) and (b) if it
is a digit, subtract '0' from it:
if (isdigit(*rit))
cout << position << (*rit - '0') * 2 << endl;
else
cerr << position << " - not a digit!!!" << endl;
> position++;
> }
> }
V
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