Reference Language | Libraries | Comparison | Changes
Arduino programs can be divided in three main parts: structure, values (variables and constants), and functions.
| StructureControl StructuresFurther Syntax
 Arithmetic OperatorsComparison Operators
 Boolean OperatorsPointer Access OperatorsBitwise Operators
 Compound Operators | VariablesConstants
 Data Types
 ConversionVariable Scope & QualifiersUtilities | FunctionsDigital I/O
 Analog I/O
 Due & Zero onlyAdvanced I/OTime
 MathTrigonometryCharacters
 Random Numbers
 Bits and BytesExternal InterruptsInterruptsCommunicationUSB (32u4 based boards and Due/Zero only)Looking for something else?See the libraries page for interfacing with particular types of hardware. Try the list of community-contributed code. 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. | 
Corrections, suggestions, and new documentation should be posted to the Forum.
The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.