JavaScript % (modulo) gives a negative result for negative numbers

javascript math modulo

Alec Gorge · Dec 17, 2010 · Viewed 82.7k times · Source

According to Google Calculator (-13) % 64 is 51.

According to Javascript (see this JSBin) it is -13.

How do I fix this?

Answer

Number.prototype.mod = function(n) {
    return ((this%n)+n)%n;
};