Reading notes-"you Don t Know JS"

Part One: "You don t know Js:this & Object Prototype" Chapter III object

Object constants

var myObject ="Favorite_number"false}) ;

Prohibit object extension

var myObject =2= 3//  undefined

using the Preventextensions method, you can prevent the object from expanding again.

Object.seal (..)
Preventextensions + Configurable:false

Object.freeze (..)
s object.seal (..) + writable:false

Object default method [[Get]], [[PUT]]

customizing getters and Setters

varMyObject = { //define a getter for ' a 'get A () {return2;}};o Bject.defineproperty (MyObject,//Target"B",//Property Name{//Descriptor //define a getter for ' B 'Getfunction(){return  This. A * 2 }, //Make sure ' B ' shows up as a object propertyEnumerabletrue });

var myObject =//  define a getter for ' a 'return This  //  define a setter for ' a 'this. _a_ = val * 2;}};