Intro to Java with Greenfoot: the year before AP CSA

A complete first-year Java course, taught by building games in Greenfoot. It starts with a student who has never opened a code editor and finishes with one who can render and navigate a 2D array tile map, which is the work AP Computer Science A spends weeks on.

Schools most often run this as the pre-AP year before AP Computer Science A, or as the first year of a two-year sequence that finishes with the AP course.

• 6 units
• 42 lessons
• 6 game projects
• 11 project tutorials
• No experience needed
• Greenfoot is free

What students can do by the end

Read and write the Java that AP Computer Science A assumes on day one: objects and methods, variables and conditionals, loops, arrays, and 2D arrays. They will have built six working games doing it, which is the part that keeps a first-year class in the room.

The six units

• Unit 1 · 6 lessons

  Unit 1: Meet Greenfoot

  Scenarios, Worlds, and Actors through The act() Method.

• Unit 2 · 7 lessons

  Unit 2: Variables, Decisions, and Input

  Variables and Types through Keyboard Input.

• Unit 3 · 9 lessons

  Unit 3: Methods, Worlds, and Constructors

  Why Write a Method through The Actor Constructor.

• Unit 4 · 7 lessons

  Unit 4: Loops and Collections of Actors

  The while Loop through Spawning with Loops.

• Unit 5 · 6 lessons

  Unit 5: Arrays

  Declaring an Array through Arrays that Drive a Game.

• Unit 6 · 7 lessons

  Unit 6: 2D Arrays and Tile Maps

  Declaring a 2D Array through Row and Column Algorithms.

How it is taught

What a teacher has to do

Greenfoot project tutorials

Eleven build-along projects with starter files and video walkthroughs, filed under the unit whose material each one uses. They are optional and they are not graded: a Greenfoot scenario runs on the desktop and cannot report itself. Use them as the reward at the end of a unit, or as the thing a student who finishes early goes and does.

• Project 1 · Unit 1: Meet Greenfoot

  The Hungry Bee

  Movement, collision detection, and the simplest possible game loop.

  Starter files Tutorial video

• Project 2 · Unit 2: Variables, Decisions, and Input

  Catch The Apple

  Keyboard control, a score that goes up, and spawning objects at random.

  Starter files Tutorial video

• Project 3 · Unit 2: Variables, Decisions, and Input

  Piano Project

  Sound, mapping many keys to many actions, and building an instrument you can play.

  Starter files Tutorial video

• Project 4 · Unit 3: Methods, Worlds, and Constructors

  Movement Essentials

  Four movement patterns in one sitting: sliding, move and rotate, steering, and gravity with a jump.

  Tutorial video

• Project 5 · Unit 3: Methods, Worlds, and Constructors

  Fire Projectile

  Shooting on the spacebar, and point-click-shoot aiming.

  Starter files Tutorial video

• Project 6 · Unit 3: Methods, Worlds, and Constructors

  Changing Worlds

  Moving between worlds on a collision while carrying the player data across.

  Starter files Tutorial video

• Project 7 · Unit 4: Loops and Collections of Actors

  Endless Runner and Open World

  Scrolling backgrounds, generating ground as you go, and an open world to explore.

  Starter files Tutorial video

• Project 8 · Unit 4: Loops and Collections of Actors

  Tower Defense

  Enemies that follow a path, towers you place, and targeting that picks what to shoot.

  Part 1 video Part 2 video

• Project 9 · Unit 4: Loops and Collections of Actors

  Interactive Calendar

  Switch statements, drawing images, and buttons that respond.

  Part 1 video Part 2 video

• Project 10 · Unit 5: Arrays

  Array Racing

  One array holding many cars, and what that buys you over ten separate variables.

  Starter code and video coming soon

• Project 11 · Unit 6: 2D Arrays and Tile Maps

  Movie Theater

  A 2D array of seats, booked and released. The clearest grid there is.

  Starter files

Common questions