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+.. _arduino-modulo:
+
+% (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
+
+
+
+Examples
+--------
+
+::
+
+    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 <http://arduino.cc/en/Reference/Arithmetic>`_
+