Find the opposite of a direction angle (360 degrees) in JavaScript

Question

The following question: https://math.stackexchange.com/questions/1319615/how-to-calculate-opposite-direction-angle shows the formula for doing this. How would I write this: (α+180) mod 360 in javascript. (a is a variable)

Answer 1

You should use the % operator:

var angle = 210;
var oppositeAngle = (angle + 180) % 360;
console.log(oppositeAngle);