How to make each input in an int cstring a single digit?

Question

What I need to do, is input an int c string from the keyboard, but each digit should be a single digit int.

For example in the running program if I would input "1234", it shouldn't read '1234', but a '1' followed by a '2', '3' and then '4'. I would submit my thought process on it, but I'm at a complete loss here.

This is in C++ by the way, and I have the restriction of not being able to use anything from the STL library.

Read a CHAR instead of string, then convert to correct int. Or, read a string with width manipulator of 1 (assuming I remember correctly that cin adheres to them :P) — quetzalcoatl, Nov 11 '13 at 20:11
`I would submit my thought process on it, but I'm at a complete loss here.` Do it anyway! — Lightness Races in Orbit, Nov 11 '13 at 20:12
One option is to read as a number and use math to isolate the digits. — Thomas Matthews, Nov 11 '13 at 20:14
Yeah it is a homework, I guess I should have said so. I was trying to do a do... while loop, but I don't think that would have reached anywhere, the char answer seems to be viable, I'll try that. Thank you very much quetzalcoalt! — user2503247, Nov 11 '13 at 20:15

score 0 · Accepted Answer · answered Nov 11 '13 at 20:22

say we have a char array of that you've gotten from the user, and that array of chars looks something like this char line[] = {'1', '2', '3', '4', '\0'}; which is basically equivalent of entering 1234 in the console.

it would then be possible to get the integer value of an indexed position in the previously mentioned array by doing something like this: int one = line[0] - '0';

this:

char line[] = {'1', '2', '3', '4', '\0'};
int one = line[0] - '0';
std::cout << one << std::endl;

will output this:

1

How to make each input in an int cstring a single digit?

1 Answers1