Different Ways of iterating through lists.

inheritanceAndIterating.js

// Adding a property to the global Object => all objects inherit from this. ex: toString method and prototype.
Object.prototype.WTF = "this should not be in your object";

function a() {
  this.unwanted = 10;
  this.crap = "dhjbjbfdjbf";
}

function child() {
  this.a = 1;
  this.b = 2;
}

//child inherits from a
child.prototype = new a();

var obj = new child();

for (var property in obj) { // Not only is this slower than Object.keys, but it also contains the parent properties
	console.log(property + ": " + obj[property]);
}

for (var property in obj) { // This will return the proper keys but it is still 50% slower than Object.keys
	if(obj.hasOwnProperty(property))
		console.log(property + ": " + obj[property]);
}

Object.keys(obj).map((e) => console.log(`key=${e}  value=${obj[e]}`)); // best way !
Object.entries(obj).forEach(([key, value]) => console.log(`key=${key} value=${value}`)); // this one is good too!