Run results for: .dot vs ['bracket'] vs [bracket] notation

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36

Browser: Chrome 79

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
dot / small object	11127640.0 Ops/sec
bracket / small object	11113150.0 Ops/sec
dot / big object	9909377.0 Ops/sec
bracket / big object	9950405.0 Ops/sec
bracket variable / small object	5574926.0 Ops/sec
bracket variable / bigobject	5006695.0 Ops/sec

Script Preparation code:

  var key = "prop25";

  // setup a tiny object
  var foo = {
   prop25: "value25"
  };
  
  // setup a really big object
  var bigObj = {};
  for (var i = 0; i < 100000; i++) {
   bigObj["prop" + i] = "value" + i;
  }

Tests:

dot / small object
var a = foo.prop25;
bracket / small object
var a = foo['prop25'];
dot / big object
var a = bigObj.prop25;
bracket / big object
var a = bigObj['prop25'];
bracket variable / small object
var a = foo[key];
bracket variable / bigobject
var a = bigObj[key];

Run results for: .dot vs ['bracket'] vs [bracket] notation

Fork of https://jsperf.com/dot-vs-square-bracket/5

dot / small object

bracket / small object

dot / big object

bracket / big object

bracket variable / small object

bracket variable / bigobject