JavaScript

Number
BigInt
String
Boolean
Null
Undefined
Symbol

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​Js - data types

​Null: This data type represents the intentional absence of a value, and is represented by the keyword null (without quotes).

Undefined: This data type is denoted by the keyword undefined (without quotes). It also represents the absence of a value though it has a different use than null. undefined means that a given value does not exist.

Symbol: A newer feature to the language, symbols are unique identifiers, useful in more complex coding. No need to worry about these for now.

Object: Collections of related data.

On line 1, log the string 'JavaScript' to the console.

​On line 2, log the number 2011 to the console.

On line 3, print 'Woohoo! I love to code! #codecademy' to the console.
On line 4, print the number 20.49 to the console.

instructions

Arithmetic operators

String Concatenation

​Inside a console.log() statement, concatenate the two strings 'Hello' and 'World'.
Create a second console.log() statement in which you concatenate the strings 'Hello' and 'World', but this time make sure to also include a space (' ') between the two words.

Properties

Methods

Methods

Built-in Objects

Built-in Objects

JavaScript Variables

Variable is a container for a value. You can think of a variable as little containers for information that live in computers memory.
Information stored in variables, such as username, account number etc.

Create a variable with a descriptive name.

1. Store or update information stored in a variable.

2. Reference or “get” information stored in a variable.

3. Reference or “get” information stored in a variable.
   
   
   

​Create a Variable: let

​If we don’t assign a value to a variable declared using the let keyword, it automatically has a value of undefined

We can reassign the value of the variable

​Create a Variable: const

Properties