Pebble C convert char to int

Question

I have read a lot of ideas how to convert a single char of a string to an integer but I'm struggling with pointers in C. I am guessing at something like:

strftime(buffer, sizeof("0000"), "%H%M", tick_time);
onedigit = atoi(&buffer[1]);

So I want to have the first digit of the time converted into an integer.

If you have a more "elegant" way to do it - let me know.

Answer 1

To get the first character as an integer you want:

onedigit = buffer[0] - '0';

This takes the first (usually ASCII) character, subtracts the (ASCII) value for 0 , leaving you with an integer value in the range 0..9.

You can easily do the same thing for other numeric characters in the string, eg to get the tens digit:

tensdigit = buffer[1] - '0';