Arduino Arithmetic Operators

This week on Adventures in Science, we look at the various arithmetic operators in C and C++, specifically, as they're used in the Arduino environment. There are only 6 main operators: assignment, addition, subtraction, multiplication, division, and modulo. We also look at compound assignment operators; how they can be used to perform a math operation on a variable and then store the result back in the same variable.

Language Reference:

Arduino programs can be divided in three main parts: structure, values (variables and constants), and functions.

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.