Animation Review

Animation Review

Let's Review counters, rotations, random numbers, and order of commands.

Counters

a counter is a variable that can track a value that is being added to or taken away from. Counters look like the purple blocks to the right.

Multiple Choice

Which of the following is a correctly written counter?

• sprite.x = +3;

• sprite.x = sprite.x + 3;

• sprite.x = 3 + sprite.x;

• sprite.x = 3;

STAMP:

a counter is written as a variable equal to itself plus or minus some amount.

You're telling the computer to make the value of the variable equal to its old value plus or minus some amount.

Check for Understanding

In the next set of questions, you'll be asked about the blocks of code to the right. Consider lines 23-25 as a group, lines 27-29 another group, and lines 31-33 a third group.

Multiple Select

Which blocks of code contain counters?

• 23-25

• 27-29

• 31-33

Open Ended

The fish move to the left and shaking as they move. The bubbles are moving up the screen. Which blocks of code make the fish shake? How do you know?

Multiple Choice

Which fish moves the slowest?

• Orange fish

• Blue fish

• Green fish

Multiple Choice

Which bubbles moves up the screen the FASTEST

• bubble1

• bubble2

• bubble3