JavaScript to compute pi

pi_compute.js

var z = 1;
var sum = 0;
var neg = false;

// uses the Taylor series for arctan(1)
while (z < 100000000 ) {
    if (neg == true) {
       sum = sum - (Math.pow(1, z) / z);
       z = z + 2;
       neg = false;
    } else {
       sum = sum + (Math.pow(1, z) / z);
       z = z + 2;
       neg = true;
    }
}

// multiply by 4 because arctan(1) = pi/4
console.log(sum * 4);