BJC AP CSP Unit 3 Exam Review

The robot starts at the bottom right, facing north. Which sequence of steps would move the sprite to where it is now?

• Turn left, move forward, turn right

• Turn left, move forward, turn right, move forward

• Move forward, turn right, move forward

• Turn right, move forward, turn left, move forward

Answer explanation

Use a pencil, pointed eraser, something with an orientation, as the robot, and move it across the page/screen.

Remember that rotate doesn't move the robot.

What is shopping list[6]?

• None of these, error, etc.

• milk

• chips

• cereal

Answer explanation

AP Exam pseudocode:

item 6 of "shopping list"

point(x,y) takes in two numbers & reports a list, [x,y]. What is the output, ignoring the words?

• [-50,20], [10, 120], [30,20]

• [-50], [10], [30]

• [-50, 10, 30]

• -50, 10, 30

Answer explanation

The last three choices are not identical. Square brackets, [], denote a list.

What is computer vision?

• where we see technological advancement in the future

• teaching computers how to "see" with software that interprets and detects

• the study of monitor displays

• the automation of jobs

A global and a local variable have the same name. Will changing the value of the global variable affect the local one?

• Yes

• No

Answer explanation

Even if they have the same name.

Global variable: When you click "Make a variable" button in the Variables palette.

Local variable: A script variable or a paramter.

Where will the sprite end up after the code above is executed?

• A

• B

• C

• D

Answer explanation

The curly brackets {} denote what is repeated before the next instruction runs. So, the first repeat has to finish before the second repeat starts.

Which brick wall could not be drawn by the block above?

• A

• B

• C

• D

Answer explanation

Check each random reporter by itself, if possible. Can only draw 2-4 full bricks per row.

Which script(s) will allow the sprite to escape the maze?

• Script A, only

• Script B, only

• Both scripts

• Neither script

Answer explanation

Write things down on paper. They work the same way.

What is output when the code above is run?

• 21

• 22

• 23

• Nothing gets displayed; this is an infinite loop

Answer explanation

Pen/pencil to draw trace table.

5, 6, 7, 8, 9, 10, 13, 16, 19, 22

Recall the Brick Wall lab. Which of the following lists the blocks in order from highest level of abstraction to lowest level? Be careful!

• A, C, B

• B, A, C

• C, A, B

• None of the above

Answer explanation

What doesn't require the others to write is the lowest abstraction. Block 1 using Block 2 means 1 is at a higher level of abstraction than 2.

C blocks use the A block, and the B block uses the C blocks.