JavaScript Tutorial/Operators/Mod
Mod operator in action
<html>
<head>
<title>A Simple Page</title>
<script language="JavaScript">
<!--
var a = 6, b = 4;
alert(a % b);
// -->
</script>
</head>
<body>
</body>
</html>
Modulus (%)
Modulus (%) operator returns only the remainder.
If either value is a string, an attempt is made to convert the string to a number.
For example, the following line of code
var resultOfMod = 26 % 3;
%= (Modulus Assignment)
The modulus assignment operator divides the value stored in the left variable by the right value. If value is a string, an attempt is made to convert the string to a number before performing the modulus and assignment.
<html>
<script language="JavaScript">
<!--
answer = 3;
answer %= 17;
document.write("answer = ",answer);
-->
</script>
</html>