Learn JavaScript

Learn how to use JavaScript — a powerful and flexible programming language for adding website interactivity.

• Welcome to Learn JavaScript
  • Informational - Welcome to Learn JavaScript
• Introduction
  • Lesson - Introduction to JavaSript
    • What is JavaScript?
    • Console
    • Comments
    • Data Types
    • Arithmetic Operators
    • String Concatenation
    • Properties
    • Methods
    • Built-in Objects
    • Review
  • Lesson - Variables
    • Variables
    • Create a Variable: var
    • Create a Variable: let
    • Create a variable: const
    • Mathematical Assignment Operators
    • The Increment and Decrement Operator
    • String Concatenation with Variables
    • String Interpolation
    • typeof Operator
    • Review Variables
  • Project - Kelvin Weather
  • Project - Dog Years
  • Quiz - Introduction to JavaScript
  • Article - JavaScript Versions: ES6 and Before
  • Article - Make the Most of Your Codecademy Membership
• Conditionals
  • Lesson - Conditional Statements
    • What are Conditional Statements?
    • If Statements
    • If...Else Statements
    • Comparison Operators
    • Logical Operators
    • Truthy and Falsy
    • Truthy and Falsy Assignment
    • Ternary Operaor
    • Else if Statements
    • The switch keyword
    • Review
  • Project - Magic Eight Ball
  • Project - Race Day
  • Quiz - Conditional Statements.
• Functions
  • Lesson - Functions
    • What are Functions?
    • Function Declarations
    • Calling a Function
    • Parameters and Arguments
    • Default Parameters
    • Return
    • Helper Functions
    • Function Expressions
    • Arrow Functions
    • Concise Body Arrow Functions
    • Review Functions
  • Project - Rock, Paper, or Scissors
  • Project - Sleep Debt Calculator
  • Quiz - Funcions
• Scope
  • Lesson - Scope
    • Scope
    • Blocks and Scope
    • Global Scope
    • Block Scope
    • Scope Pollution
    • Practice Good Scoping
    • Review: Scope
  • Project - Training Days
  • Quiz - Scope
• Arrays
  • Lesson - Arrays
    • Arrays
    • Create an array
    • Accessing Elements
    • Update Elements
    • Arrays with let and const
    • The .length proprety
    • The .push() Method
    • The .pop() Method
    • More Array Methods
    • Arrays and functions
    • Nested Arrays
    • Review Arrays
  • Project - Secret Message
  • Quiz - Arrays
• Loops
  • Lesson - Loops
    • Loops
    • Repeating Tasks Manually
    • The For Loop
    • Looping in Reverse
    • Looping Through Arrays
    • Nested Loops
    • The While Loop
    • Do...While Staements
    • the Break Keyword
    • Review
  • Project - Whale Talk
  • Quiz - Loops
• Iterators
  • Lesson - Higher-Order Functions
    • Introduction
    • Functions as Data
    • Function as Parameters
    • Review
  • Lesson - Iterators
    • Introduction to Iterators
    • The .forEach() Method
    • The .map() Method
    • The .filter() Method
    • The .findIndex() Method
    • The .reduce() Method
    • Iterator Documentation
    • Choose the rigth Iterator
    • Review
  • Quiz - Higher Order Funcions and Iterators
  • Project - Grammar Checker
• Objects
  • Lesson - Objects
    • Introduction to Objects
    • Creating Object Literals
    • Accessing Properties
    • Bracket Notation
    • Property Assignment
    • Methods
    • Nested Objects
    • Pass by Reference
    • Looping Through Objects
    • Review
  • Lesson - Advanced Objects
    • Advanced Objects Introduction
    • The this Keyword
    • Arrow Functions and this
    • Privacy
    • Getters
    • Setters
    • Factory Functions
    • Property Value Shorthand
    • Destructured Assignment
    • Buid-in Objects Methods
    • Review
  • Project - Meal Maker
  • Project - Team Stats
  • Quiz - Objects
• Next Steps