Learn JavaScript, one short page at a time

These are the course notes of the School of Scriptology: 218 pages that start at “what is code?” and finish with you building real apps. Every page is free, most take two or three minutes, and the examples run right on the page.

Start at page one Or learn by playing

Kiddie School

What JavaScript is, and your very first program.

Preschool: What on Earth Is JavaScript?

Before we write code, let's figure out what code even is. Seven pages, about 13 minutes.

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  1. What Is Programming?
  2. Meet JavaScript: The Language of the Web
  3. HTML, CSS & JavaScript: The House Analogy
  4. A Short (and Slightly Silly) History of JavaScript
  5. Where Does JavaScript Live?
  6. Why Learn JavaScript?
  7. Recap

Kindergarten: Your Coding Playground & First Program

Set up your tools, say hello to the world, and learn the grammar of JavaScript. Nine pages, about 18 minutes.

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  1. Your Toolbox
  2. Meet the Console
  3. Your First Program: Hello, World!
  4. Writing JavaScript in a File
  5. Running JavaScript with Node.js
  6. The Grammar of JavaScript
  7. Comments: Notes to Your Future Self
  8. Talking to the User: alert, prompt and confirm
  9. Recap

Elementary School

Variables, data types, operators, decisions and loops.

Grade 1: Variables: Boxes With Labels

Teach your program to remember things. Nine pages, about 14 minutes.

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  1. What Is a Variable?
  2. Creating Variables with let
  3. const: Boxes With Locks
  4. var: Grandpa's Old Box
  5. Naming Your Variables
  6. Declaring, Assigning, and undefined
  7. Variables Working Together
  8. Mini Project: The Café Receipt
  9. Recap

Grade 2: Data Types: What Goes in the Boxes?

Text, numbers, true and false, and two different kinds of nothing. Thirteen pages, about 17 minutes.

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  1. The Kinds of Things in the Boxes
  2. Strings: Text in Quotes
  3. Template Literals: The Easy Way to Build Strings
  4. String Superpowers
  5. Numbers
  6. The Weird Numbers: NaN, Infinity and 0.1 + 0.2
  7. Booleans: True or False
  8. undefined and null: Two Kinds of Nothing
  9. typeof: What's in the Box?
  10. Type Conversion: Changing Types on Purpose
  11. Type Coercion: JavaScript's Surprise Gifts
  12. Mini Project: The Message Analyzer
  13. Recap

Grade 3: Operators: Math, Comparisons & Logic

Doing things with values: adding, comparing, and combining. Eleven pages, about 14 minutes.

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  1. Arithmetic Operators: Math Class Is Back
  2. Order of Operations
  3. Assignment Shortcuts
  4. Increment and Decrement: ++ and --
  5. Comparison Operators
  6. Equality: Why === Beats ==
  7. Logical Operators: AND, OR, NOT
  8. The Math Object: A Calculator in Your Pocket
  9. Mini Project 1: The Pizza Party Calculator
  10. Mini Project 2: The Dice Roller
  11. Recap

Grade 4: Making Decisions: if, else & Friends

Your code learns to choose its own adventure. Eleven pages, about 13 minutes.

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  1. Making Decisions with if
  2. else: The Backup Plan
  3. else if: More Than Two Choices
  4. Truthy and Falsy
  5. Combining Conditions
  6. Nested Decisions
  7. The Ternary Operator: if/else in One Line
  8. The switch Statement
  9. Mini Project: The Cinema Ticket Machine
  10. Mini Project: The Magic 8-Ball
  11. Recap

Grade 5: Loops: Doing Things Over and Over

Computers never get bored. Let's take advantage of that. Eleven pages, about 15 minutes.

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  1. Why Loops?
  2. The while Loop
  3. Infinite Loops: Buggsy's Favorite Trap
  4. The for Loop
  5. The do...while Loop
  6. break and continue
  7. Looping Over Strings
  8. Loops Inside Loops
  9. The Classic: FizzBuzz
  10. Mini Project: The Number Guessing Game
  11. Recap

Middle School

Functions, arrays and objects: the big three.

Grade 6: Functions: Your Own Custom Commands

Write it once, use it a thousand times. Eleven pages, about 16 minutes.

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  1. What Is a Function?
  2. Declaring and Calling a Function
  3. Parameters and Arguments
  4. Return Values
  5. Default Parameters
  6. Function Expressions
  7. Arrow Functions
  8. Functions Working Together
  9. Good Function Habits
  10. Mini Project: The Converter Toolkit
  11. Recap

Grade 7: Arrays: Lists of Things

One variable, many values, all in a neat little row. Fourteen pages, about 16 minutes.

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  1. What Is an Array?
  2. Reading Items (and Why We Count From Zero)
  3. length and the Last Item
  4. Changing Items
  5. Adding and Removing Items
  6. Finding Things in an Array
  7. Slicing and Splicing
  8. Looping Over Arrays
  9. Arrays and Strings: split and join
  10. Combining and Copying Arrays
  11. Sorting Arrays (and a Sneaky Surprise)
  12. Arrays Inside Arrays
  13. Mini Project: The Shopping List Manager
  14. Recap

Grade 8: Objects: Describing Things With Labels

Keys, values, and the secret identity of `console.log`. Thirteen pages, about 15 minutes.

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  1. What Is an Object?
  2. Creating Objects
  3. Reading Properties: Dot and Bracket Notation
  4. Adding, Changing and Deleting Properties
  5. Methods: Functions Inside Objects
  6. A First Look at this
  7. Nested Objects and Arrays of Objects
  8. Looping Over Objects
  9. Shortcuts: Shorthand and Destructuring
  10. Copying Objects (and the Reference Trap)
  11. JSON: Objects as Text
  12. Mini Project: The Report Card Generator
  13. Recap

Summer School

Bugs, errors, and how to squash them.

Summer School: Debugging: Becoming a Bug Detective

Errors aren't failures. They're clues. Eleven pages, about 18 minutes.

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  1. Bugs Happen (to Everyone)
  2. The Three Kinds of Bugs
  3. Meet the Error Family
  4. Reading an Error Message
  5. console.log: Your Flashlight
  6. The Debugger: Pausing Time
  7. Handling Errors with try...catch
  8. Throwing Your Own Errors
  9. Rubber Duck Debugging
  10. The Top 12 Beginner Bugs
  11. Recap

High School

Closures, array power tools, the DOM, events and modern JS.

Grade 9: Scope, Hoisting & Closures

Who can see what, and the function that never forgets. Eleven pages, about 14 minutes.

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  1. What Is Scope?
  2. Global Scope: The Hallway
  3. Function Scope: Your Bedroom
  4. Block Scope: Your Closet
  5. Why var Leaks Out of Blocks
  6. Shadowing: When Names Collide
  7. The Scope Chain
  8. Hoisting
  9. Closures: Functions With Backpacks
  10. Mini Project: The Secret Vault
  11. Recap

Grade 10: Array Power Tools: map, filter & reduce

Why write a loop when one line will do? Twelve pages, about 14 minutes.

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  1. Callbacks: Functions as Ingredients
  2. forEach: Loop Without the Loop
  3. map: Transform Every Item
  4. filter: Keep Only Some
  5. find and findIndex: Get the First Match
  6. some and every: Yes-or-No Questions
  7. reduce: Boil It Down to One Value
  8. sort With a Comparator (Finally Explained)
  9. Chaining: Building a Data Pipeline
  10. Other Handy Array Tricks
  11. Mini Project: The Movie Night Dashboard
  12. Recap

Grade 11: The DOM: Taking Control of Web Pages

Reach into a web page and change anything you like. Ten pages, about 13 minutes.

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  1. What Is the DOM?
  2. Your Practice Page
  3. Selecting Elements
  4. Changing Text and HTML
  5. Changing Styles
  6. Working With Attributes
  7. Creating, Adding and Removing Elements
  8. Walking the Tree
  9. Mini Project: The Team Page
  10. Recap

Grade 12: Events: Making Pages React

Clicks, keys, forms, and a page that remembers you. Nine pages, about 15 minutes.

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  1. What Are Events?
  2. addEventListener
  3. The Most Common Events
  4. The Event Object
  5. Forms and Inputs
  6. Event Bubbling and Delegation
  7. Remembering Things with localStorage
  8. Mini Project: The Dark Mode Switch
  9. Recap

Grade 13: Modern JavaScript Power-Ups

Small bits of syntax that make a big difference. Twelve pages, about 14 minutes.

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  1. Welcome to Grade 13
  2. Spread: Unpacking Everything
  3. Rest: Packing Things Up
  4. Destructuring Deluxe
  5. Optional Chaining: ?.
  6. Nullish Coalescing: ??
  7. Short-Circuit Tricks
  8. Sets: Collections of Unique Values
  9. Maps: Flexible Key-Value Pairs
  10. Working With Dates
  11. Mini Project: The Data Cleaner
  12. Recap

College

Async code, classes, modules and real projects.

Freshman Year: Asynchronous JavaScript: Waiting Without Freezing

Timers, promises, async/await and fetching data from the internet. Ten pages, about 18 minutes.

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  1. Synchronous vs Asynchronous
  2. Timers: setTimeout and setInterval
  3. Callbacks and the Pyramid of Doom
  4. Promises: An IOU for a Future Value
  5. async and await: Code That Reads Like a Story
  6. Doing Things in Parallel: Promise.all
  7. Fetching Data From the Internet
  8. The Event Loop: How It All Works
  9. Mini Project: The Burger Kitchen Simulator
  10. Recap

Sophomore Year: Classes & Object-Oriented JavaScript

Blueprints, cookie cutters, and the mystery of `this` solved. Eleven pages, about 16 minutes.

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  1. Why Classes?
  2. Your First Class
  3. Getters and Setters
  4. Static Methods and Properties
  5. Private Fields
  6. Inheritance: extends and super
  7. The Mystery of this, Solved
  8. Prototypes: What Classes Really Are
  9. When Should You Use Classes?
  10. Mini Project: Virtual Pets
  11. Recap

Junior Year: Modules, Node.js & npm: Working Like a Pro

Split your code into files, run it anywhere, and borrow from millions of packages. Eleven pages, about 17 minutes.

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  1. Why Modules?
  2. Exporting and Importing
  3. Modules in the Browser
  4. Node.js: JavaScript Outside the Browser
  5. Reading and Writing Files
  6. Command-Line Arguments
  7. npm: The World's Biggest Toolbox
  8. Testing Your Code
  9. Mini Project: The Expense Tracker CLI
  10. The Professional Developer's Toolbox
  11. Recap

Senior Year: Capstone Projects: Build Real Apps

Three complete projects. Everything you've learned, working together. Seven pages, about 26 minutes.

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  1. How to Build a Project
  2. The State + Render Pattern
  3. Project 1: Tasky, the To-Do List
  4. Project 2: The CurlyScript Quiz Show
  5. Project 3: Sky Check, the Weather App
  6. You Built Three Apps!
  7. Recap

Graduation

What to do after the last grade.

Graduation: Graduation and beyond

Five pages, about 8 minutes.

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  1. Graduation Day
  2. Where to Go From Here
  3. A 30-Day Practice Plan
  4. The Best Free Resources
  5. Habits of Great Developers

Keep these open

The glossary

76 programming words, from API to variable, in plain English.

The cheat sheet

The syntax you’ll look up most, on one page: variables, loops, functions, arrays, objects and more.

Reading is step one

CurlyScript turns these notes into a game: short questions, an explanation after every answer, and a test at the end of each grade. Free, with nothing to sign up for.

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