monte-carlo-PI.js

const n = 100000;
let hit = 0;
for (let i = 0; i < n; i++) {
  const x = Math.random();
  const y = Math.random();
  if (x *x + y * y < 1) {
  	hit += 1;
  }
}
console.log(4.0 * hit / n);