public/subjects/object

Object

This exercise is about structuring multiple values together.

Data Structures: Objects

In JS, Object are the most basic data structures, they are a way to group values together.

They are like a bag of values.

Example

Remember that they are different types of variables:

let currency = 'EURO'
let amount = 77.5
let cashPayment = false

Now we can group them all in an object, as objects are values too, let's assign one to a transaction variable:

let transaction = {
  currency: 'EURO',
  amount: 77.5,
  cashPayment: false,
}
console.log(transaction) // will show the object transaction

The variable transaction is declared and its value type is an object.

Let's explain each parts:

Object litteral syntax: {}

Starting with curly brackets {}, they are the delimiters of our object.

let empty = {} // an empty object

Properties

They define what we want inside our objects. They are composed of two elements:

• a key
• and a value

//                 ↙ begining of the declaration
let transaction = {
  //  ↙ property key
  currency: 'EURO',
  //           ↖ property value
}
// ↖ end of the declaration

We separate them with a :, to simplify, we will only use valid identifiers as keys at the moment.

Each properties must be separated with a ,

Note that it's easier to always add a trailing , on every properties, but it is not required for the last property.

Instructions

Declare a variable human which has a value an object with 3 properties:

• a name property of your name as a String
• an age property of your age as a Number
• a secureLuggage of a Boolean saying if your luggage contain dangerous things or not. (still, for obvious security reasons)

“I paint objects as I think them, not as I see them.”
― Pablo Picasso