Javascript property access speed: difference var.property vs. var[“property”]?

Question

I have a very basic JavaScript question.

I am writing a program which will generate JavaScript code. for accessing a property of a variable i have two choices:

Answer 1

I did this test on Node.JS

var obj = {test:"test"}

var time1 = new Date();
var t1 = time1.getTime();  

for(i = 0; i < 1000000000; i++){
  obj.test;
}

var time2 = new Date();
var t2 = time2.getTime();

console.log(t2-t1)

var time3 = new Date();
var t3 = time3.getTime();

for(i = 0; i < 1000000000; i++){
  obj["test"];
}

var time4 = new Date();
var t4 = time4.getTime();

console.log(t4-t3)  

I find both perform almost the same, with obj.test performing a tiny bit better than obj["test"]