test.js

var values = [...new Array(32000000)].map((_, i) => i);

console.time('map + reduce');
window.sum1 = values.map(x => x*x).reduce( (total,num,index,array) => total+num,0.0);
console.timeEnd('map + reduce');

console.time('reduce');
window.sum2 = values.reduce( (total,num,index,array) => total+num*num,0.0);
console.timeEnd('reduce');


console.time('for loop');
var sum = 0.0;
for (var i = 0; i < values.length;i++){
	var x = values[i];
	sum += x*x;
}
window.sum3 = sum
console.timeEnd('for loop');