Properties

A property is similar to a field except that you do not have to use additional methods to manage your private fields.

Auto Implemented Properties

Adding the public keyword.

class myClass { 
   constructor(public property_name: string) {} 
} 
let myObject = new myClass("Monday"); 
console.log( myObject.property_name )  // "Monday" 

replaces

class myClass { 
   property_name: string; 
   constructor(name: string) { 
      this.property_name = name; 
   } 
} 
let myObject = new myClass("Monday"); 
console.log( myObject.property_name )  // "Monday" 

Accessing

You can access properties using a string value
All the keys are converted to string type in the square bracket

myObject.Property1 
myObject['Property 2'] 
myObject['']        //blank string  

var myString = 'Property3';  
myObject[myString]     // you can use variables 

var myNumber = math.random(); 
myObject[myNumber] 

var myObject2 = new Object(); 
myObject[myObject2]              // this uses myObject2.toString() 

var myObject = { 
   Property1 : 10, 
   get Property1_Get() { 
      return this.Property1; 
   } 
} 

var myObject = { 
   Property1 : 10, 
   set Property1_Set(val) { 
      this.Property1 = val; 
   } 
} 

Properties

function class_Example(name, address) { 
   // private fields 
   var _name = "some text"; 

   Object.defineProperty(this, "name", 
      get: function() { return _name; } 
      set: function(value) { _name = value; } 
   }); 
} 
var myObject = new class_Example("one","two"); 
var string1 = myObject.name 

Add Properties Dynamically

You can add properties to an object by just defining them

myobject.Property_AnotherOne = "something else"; 

All object properties are mutable, ie changeable

Assigning Properties

function myFunction(arg1, arg2, arg3) { 
   myFunction.Property_Value1 : arg1; 
   myFunction.Property_Value2 : arg2; 
   myFunction.Property_Value3 : arg3; 
} 
function myFunction(arg1, arg2, arg3) { 
   myFunction.Property_Value1 = arg1; 
   myFunction.Property_Value2 = arg2; 
   myFunction.Property_Value3 = arg3; 
} 

The 'this' keyword is used inside a function to refer to the object the function is contained within.
Which is also equivalent to

function myFunction(arg1, arg2, arg3) { 
   this.Property_Value1 : arg1; 
   this.Property_Value2 : arg2; 
   this.Property_Value3 : arg3; 
} 

This is equivalent to

function myFunction(arg1, arg2, arg3) { 
   this.Property_Value1 = arg1; 
   this.Property_Value2 = arg2; 
   this.Property_Value3 = arg3; 
} 

This is equivalent to

Enumerating

for - in was added in ES 2009
This traverses all enumerable properties of an object

var Utilities = { 
   Method_ShowAllMembers : function(targetObject) { 
      for (member in targetObject) { 
         document.write("<br />" + targetObject[member]); 
      } 
   } 
   Method_ShowAllMembersAndValues : function(targetObject) { 
      for (member in targetObject) { 
         document.write("<br />" + member + " == > " + targetObject[member]); 
      } 
   } 
} 

Utilities.Method_ShowAllMembers(myObject); 
Utilities.Method_ShowAllMembersAndValues(myObject); 

Object.keys(myObject)
Object.getOwnPropertyNames(myObject)