Language Reference
Arduino programs can be divided in three main parts: structure, values (variables and constants), andfunctions.
Structure
setup()
loop()
Control Structures
if
if...else
for
switch case
while
do... while
break
continue
return
goto
Further Syntax
; (semicolon)
{} (curly braces)
// (single line comment)
/* */ (multi-line comment)
#define
#include
Arithmetic Operators
= (assignment operator)
+  (addition)
- (subtraction)
* (multiplication)
/ (division)
% (modulo)
Comparison Operators
== (equal to)
!= (not equal to)
< (less than)
> (greater than)
<= (less than or equal to)
>= (greater than or equal to)
Boolean Operators
&& (and)
|| (or)
! (not)
Pointer Access Operators
* dereference operator
& reference operator
Bitwise Operators
& (bitwise and)
| (bitwise or)
^ (bitwise xor)
~ (bitwise not)
<< (bitshift left)
>> (bitshift right)
Compound Operators
++ (increment)
-- (decrement)
+= (compound addition)
-= (compound subtraction)
*= (compound multiplication)
/= (compound division)
%= (compound modulo)
&= (compound bitwise and)
|= (compound bitwise or)
Variables
Constants
HIGH | LOW
INPUT | OUTPUT | INPUT_PULLUP
LED_BUILTIN
true | false
integer constants
floating point constants
Data Types
void
boolean
char
unsigned char
byte
int
unsigned int
word
long
unsigned long
short
float
double
string - char array
String - object
array
Conversion
char()
byte()
int()
word()
long()
float()
Variable Scope & Qualifiers
variable scope
static
volatile
const
Utilities
sizeof()
PROGMEM
Functions
Digital I/O
pinMode()
digitalWrite()
digitalRead()
Analog I/O
analogReference()
analogRead()
analogWrite() - PWM
Due & Zero only
analogReadResolution()
analogWriteResolution()
Advanced I/O
tone()
noTone()
shiftOut()
shiftIn()
pulseIn()
Time
millis()
micros()
delay()
delayMicroseconds()
Math
min()
max()
abs()
constrain()
map()
pow()
sqrt()
Trigonometry
sin()
cos()
tan()
Characters
isAlphaNumeric()
isAlpha()
isAscii()
isWhitespace()
isControl()
isDigit()
isGraph()
isLowerCase()
isPrintable()
isPunct()
isSpace()
isUpperCase()
isHexadecimalDigit()
Random Numbers
randomSeed()
random()
Bits and Bytes
lowByte()
highByte()
bitRead()
bitWrite()
bitSet()
bitClear()
bit()
External Interrupts
attachInterrupt()
detachInterrupt()
Interrupts
interrupts()
noInterrupts()
Communication
Serial
Stream
USB (32u4 based boards and Due/Zero only)
Keyboard
Mouse
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 manualfor details.
Reference Home
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.
https://www.arduino.cc/en/Reference/HomePage