js_math

function randomPointOnCircle(radius) {
// Pi or π is a mathematical constant equal to a
// circle's circumference divided by its diameter.
    var angle = Math.random() * 2 * Math.PI;
// Math.random() 0 - 1 pseudorandom number in that range
    return {x: radius * Math.cos(angle),
            y: radius * Math.sin(angle)};
}
console.log(randomPointOnCircle(2));

function randomZeroToN(n) {
    return Math.floor(Math.random() * n);
}
// Generate random number 0 - n
var counter = 0;
do {
    console.log(randomZeroToN(100));
    counter++;
} while (counter < 10);