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en:reference:language:modulo

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 — en:reference:language:modulo [2017/04/07 10:03] (current) 2014/11/13 14:35 弘毅 created 2014/11/13 14:35 弘毅 created Line 1: Line 1: + ====== % (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. +