Every object in Scratch is a sprite which can have scripts to define its behavior and costumes to define its appearance. The stage is where all sprites are placed and can also contain scripts, which is useful for scripts not specific to individual sprites. Scripts start with the green flag and contain statements and conditions to control program flow. Loops are used to repeat statements either continuously or a set number of times. Variables store values and have a scope of either global across all sprites and stage or local to a single sprite. Events trigger sprite behaviors and broadcasting allows sprites to communicate through signaling and handling custom events. Threads allow simultaneous processes in Scratch.

2. Sprites
• Every object is a sprite
• Two cats = two sprites
• Sprites have:
• Scripts (how the script ‘behaves’)
• Costumes (what the sprite looks like)

3. Stage
• Where all sprites are placed
• The stage can also have scripts
• Useful when scripts aren’t specific to an actual
sprite
• Instead of costumes, has backdrops

4. creating scripts: entry point
• Begin the program with pressing the green flag

5. statements
• Where the action is

6. booleans, conditions
• Ask a true/false
question…
• …And do something
based on the answer.

7. conditions
{a fork in the road}

9. loops
• Used to repeat statements:
• Continuously
• For a set number of times
• Until a certain condition is true

10. loops: avoid this

11. much better!

12. variables
• Contain values
• In Scratch: Numbers and words

13. variables: scope
• Global (stage + all sprites)
• Local (one sprite only)
• Who needs to use the variable?

14. events
• How the sprite behaves when…

15. broadcasting events
• Allows sprites to communicate
• Signal an event:
• Handle an event:

16. threads
• Simultaneous processes