Javascript Object
Object-oriented Programming: encapsulation, inheritance

// Array
var person1 = ["Raymond", 33, "Walnut Creek"]
var person2 = ["Yuhua", "Walnut Creek", 38]

// Object
var person = {
    name: "Raymond",
    age: 33,
    city: "Walnut Creek"
};

array vs. object:
array has strict order; while object is key-value pairs

// access object property:
person.name - dot notation
person["name"]  - has better tolerance in name:  "start with number", variable, space in name

Object initialization:
// option 1
var person = {};
person.name = "raymond"

var person = {
    name: "raymond",
    age: 23
};

// option 2
var person = new Object();
person.name = "raymond"

// option 3
// constructor - class
function Person() {
  this.name = "person";
  this.age = 0;
  this.race = "";
}
Person.prototype.greeting = function() {
  console.log("Hello, I am " + this.name);
}

var pObj = new Person();

Object.keys(); values(); entries();
prototypes


JSON - JavaScript Object Notation
data serialization for passing JSON message over the Internet
JSON.stringify();
JSON.parse()

For example, a project web page to be expressed as:
var webpage = {
  title: "An IoT Wand",
  description: "describe project details here",
  steps:
      ["step 1 - xxxxxx",
       "step 2 - yyyyyy"]
  pictures: [
      {"pic 1 title", "image/pic1.jpg"},
      {"pic 2 title", "image/pic2.jpg"}
  ]
}