var a = Object.create(null); is not the same as var a = {}; var a = Object.create(null); sets the prototype of a as null where as var a = {}; sets the prototype of a as the Object object
var a = Object.create(null); is not the same as var a = {};
var a = Object.create(null); sets the prototype of a as null where as
var a = {}; sets the prototype of a as the Object object