Just Enough JavaScript - getfutureproof/fp_guides_wiki GitHub Wiki

Just enough JavaScript to get going!

Data Types

name	description
string	`“Hello world”`
number	`1`
boolean	`true / false`
null	`null` - represents intentional absence of value
undefined	`undefined` - value assigned to newly declared variables
symbol	`Symbol(‘Earth’)` - used to make a unique identifier. This is a newer data type.
bigint	`10n` - used to reliably represent whole numbers larger than 2^53 - 1

name	description
array	`[“Zelda”, “Tigerlily”, “Flora”]`
object	`{ name: “Zelda, age: 3 }`
function	`function (num) { return num + 3 }` \ `num => num + 3` - this is the ‘new’ arrow notation of ECMAScript 2015

name	description
var	Function or global scope. Does not have to be initialized to a value
let	Block scoped. Does not have to be initialized to a value
const	Block scoped. Must be initialized to a value. Cannot be reassigned

operator	description
`+ - / *`	Add, subtract, divide, multiply
`**`	exponentiation - ‘to the power of’.
`%`	modulo - returns whole number remainder of a division eg `5%3 => 2`
`=`	assignment - assigns a value to a variable.
`==`	equal - returns true if both sides are equal (does not check for data type)
`===`	strict equal - returns true if both sides are equal and of same data type
`!`	logical NOT - eg. `!true => false`

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