<!DOCTYPE html>
<html lang="en-US">
<body>
<h1>JS Sum of Digits</h1>
<script>
var num = 12345;
var copyNum = num;
var total = 0;
//Add Each digit from last digit.
while(copyNum != 0)
{
total += copyNum % 10;
copyNum = Math.floor(copyNum / 10);
}
//result
document.write("The sum of digit " +num +" is " +total);
</script> </body>
</html>