Convert from ascii to int

Dear all, how can I convert from ascii to integer??

Is there any formula?

Tnx

standard C funtion called atoi

int atoi ( const char * str );

This question comes up all the time. Why isn't in the Reference section I wonder?

atoi() is a function that is part of the AVR libc library The Reference homepage provides the following info:

The Arduino language is based on C/C++. It links against AVR Libc and allows the use of any of its functions; see its user manual for details.

with links to the Libc reference and user manual.

So, in short, it is in the Reference section.

Another more flexible option is strtol() http://avr-libc.nongnu.org/user-manual/group__avr__stdlib.html#gaf8ce3b8dae3d45c34c3b172de503f7b3

Three days ago:

http://arduino.cc/forum/index.php/topic,51209.0.html