CS 122 - Quiz 1

Solution

Here's my solution to problem 1. It is a simple loop with a single if command to check whether the sprite is over x coordinate zero.
Problem 1 Solution

Here's my solution to problem 2. Note that the cats and dogs don't do all that much, most of the logic is in the ref sprite
Problem 2 Solution

Posted Monday, July 27

Problem 1

Loops and Conditionals

Use the default cat sprite and stamp its image on the stage to make the following image. You must use a repeat loop, moving the sprite within the loop between stamps.

All the stamps are along the x-axis, so the y-coordinate is always 0. The first stamp location is at x-coordinate -180. You can move to this location before the repeat loop, but all other movement must take place inside the loop.

The cat should be stamped at the following x-coordinates:

-180
-120
-60
60
120
180

Do not stamp at x-coordinate 0.

There are many ways to solve this problem and you are free to use anything you can come up with as long as your solution uses a loop and no more than one movement command in each iteration of the loop. You will also need a conditional statement to avoid stamping at x-coordinate 0.

screenshot of desired output for Problem 1

Problem 2

Messages and Variables

For this problem, create a Scratch project with 3 cat sprites, 3 dog sprites, and a robot sprite. The exact placement of the sprites is not important, and you made need to shrink them to make them all fit on the stage. You should end up with a program looking something like this:

screenshot of stage setup for Problem 2

The program should have the following behaviors:

The robot will keep track of how many times a cat has been clicked on and how many times a dog has been clicked on.
When a cat is clicked on, it should disappear and the robot should say "cat count #", where '#' is the total number of times a cat has been clicked on.
When no cats are visible on the screen, they should all reappear (hint: you can use the mod operator to figure out if the total number of cat or dog clicks is an even multiple of three, which is when they should reappear)
The dogs have exactly the same behavior as the cats, except that the robot announces the total number of dogs clicked on instead of the total number of cats clicked on (by saying "dog count #" where '#' is the total number of times a dog has been clicked on).
If the robot is clicked it will say "cat count is #" for one second, then "dog count is #" for one second, then "total count is #" for one second; where '#' is replaced with the number of times that thing has been clicked. The "total count" # is the number of cat clicks plus the number of dog clicks.
When the green flag is clicked, all counts should reset to zero and all sprites should appear.

Submit

Use this form to submit your quiz solutions. Note that just like an assignment, you can submit more than once if you realize that you made a mistake on a submission.

Student number (no dashes):: This is the 9-digit number on your student body card. It probably starts 950 or 951 and it looks something like this: 950123456. This number is used to identify your submission so please enter it carefully.
Name (first and last):
Email address:
Your solution to problem 1: Attach the scratch file with your solution to just the first problem
Your solution to problem 2: Attach the scratch file with your solution to just the second problem