% (modulo)
Description
Calculates the remainder when one integer is divided by another. It is useful for keeping a variable within a particular range (e.g. the size of an array).
Syntax
result = dividend % divisor
Parameters
dividend
: the number to be divided
divisor
: the number to divide by
Returns
the remainder
Example
x = 7 % 5; // x now contains 2 x = 9 % 5; // x now contains 4 x = 5 % 5; // x now contains 0 x = 4 % 5; // x now contains 4
Example Code
/* update one value in an array each time through a loop */ int values[10]; int i = 0; void setup() {} void loop() { values[i] = analogRead(0); i = (i + 1) % 10; // modulo operator rolls over variable }
Tip
The modulo operator does not work on floats.
See also
- division
The text of the 86Duino reference is a modification of the Arduino reference, and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.