The Arduino "language" is actually C/C++. GNU GCC and tool chain are used. The Arduino IDE uses a preprocessor to make it easier for beginners by removing some of the C/C++ requirements such as forward declaration of functions.

The GNU GCC data types and representation, and the answer to your question can be found on the project Wiki page; https://gcc.gnu.org/wiki/avr-gcc

For C/C++ there are build-in data types but also a set of standards. One of the standard header files with data types is stdint.h.

Arduino.h and additional header files within the Arduino core libary contains the extensions or redefinitions made.

Cheers!

The Arduino "language" is actually C/C++. GNU GCC and tool chain are used. The Arduino IDE uses a preprocessor to make it easier for beginners by removing some of the C/C++ requirements such as forward declaration of functions.

The GNU AVR GCC data types and representation, and the answer to your question can be found on the project Wiki page; https://gcc.gnu.org/wiki/avr-gcc

For C/C++ there are build-in data types but also a set of standards. One of the standard header files with data types is stdint.h. http://www.nongnu.org/avr-libc/user-manual/group__avr__stdint.html

Arduino.h and additional header files within the Arduino core libary contains the extensions or redefinitions made. The complete reference list; https://www.arduino.cc/en/Reference/HomePage

Cheers!