literals.js

//////////////////////////////////////
// LONG WAY //////////////////////////
//////////////////////////////////////

var person = {} // same as "new Object()"
person.name = "sean"

person.friends = []

var friend = {}
friend.name = "isaac"

person.friends.push(friend)

console.log(JSON.stringify(person)) // -> {name:"sean", friends:[{name:"isaac"}]}

////////////////////////////////////
// Object Literals /////////////////
////////////////////////////////////
// Instead you can just write the whole object at once. 
// this looks just like JSON (JavaScript Object Notation)

var person = {
  name: "sean",
  friends: [
    {name: "isaac"}
  ]
}

console.log(JSON.stringify(person)) // same as obove

// You can take the JSON.stringify() output of any object, paste it into your editor as "var something = xxx" and it will work. 

properties.js

var person = {}
// these are the same
person.name = "sean"
person["name"] = "sean"

// useful if you want to do something like this:
// monthId is different in each iteration of the loop, so we can't use person.xxxxx
// lets you make the name of the property be a variable
for (var i = 0; i < 24; i++) {
  var monthId = "month" + i
  person[monthId] = 0
  // or you could set it to a whole object
  person[monthId] = {id: monthId, budget: 0}
}

console.log(JSON.stringify(person)) // {name:"sean", month0: 0, month1: 0, month2: 0, ...etc }

// You can loop through the property names of an object if you don't know them. 

for (var propertyName in person) {
  console.log(propertyName) // "name", "month0", "month1", etc. 
}

// You can get an array of property names and loop through them like normal
var propertyNamesArray = Object.keys(person)
propertyNamesArray.forEach(function(propertyName) {
  console.log(propertyName) // same as above
})