You know about Arrays right? An array is an ordered collection of data. Similarly, an object is an unordered collection of data.

Let’s look at an array:

const justiceLeague = ['Batman', 'Superman', 'Martian Manhunter', 'Wonder Woman', 'Hawk Girl', 'Flash', 'Green Lantern'];

So I have this array (or ordered list called justiceLeague with 7 members in in.

An array is an ordered list, where:

[

0: 'Batman',

1: 'Superman',

2: 'Martian Manhunter',

3: 'Wonder Woman',

4: 'Hawk Girl',

5: 'Flash',

6: 'Green Lantern'

]

The first item is always placed at zero 0 because, binary!

So if I have to call the first member of the justice league, I will have to call justiceLeague[0]

Okay, now that you get an overview of Arrays, let’s talk about JavaScript objects.

In JavaScript, objects are typed inside curly braces {}

They are just like arrays, but they are not an ordered list.

Let’s have a look:

const crimeSyndicate = {

boss: 'Superwoman',

second_in_command: 'Owlman',

third_in_command: 'Ultraman',

sub_boss: 'Power Ring',

henchman: 'Johnny Quick',

second_henchman: 'White Martian',

third_henchman: 'Jessica Cruz'

}

So with this format, there is not first or last member, they are all designated with their respective key ‘s.

So if I were to call the boss of this object, I would do so like this: crimeSyndicate['boss'] which would return the value ‘Superwoman’.

Just like arrays, you can have sub properties of an object:

const superHero = {

name: 'Barry Allen',

super: {

super_hero_name: 'Flash',

power: 'Super Speed'

}

}

So if I do this: superHero['super']['power'] I will get an output of ‘Super Speed’.

There is another neat way to call this, superHero.super.power will output the same result, this is called a dot notation.

Objects can also have functions as its members, I talked about it in my next post: Creating The Infinity Gauntlet of Thanos with JavaScript Objects.

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