Reference no: EM13883

Scratch Pre-Test

These pre-test questions are for getting your background knowledge on Scratch and computing concepts.

Part-1

1. What is the most basic element of a scratch script?

2. What are the two main elements of a(n) Sprite/Object?

3. Can an object affect another object without you, the programmer, specifically allowing it?

4. In a script, in what order are blocks executed?

5. Can multiple scripts/methods run at the same time?

6. In Scratch, can objects/sprites be created, destroyed, or deleted once the program has started?

Part-2

1. What are two different types of input?

2. Scripts are made up of one or more _____?

3. Explain the flow of execution in a script/method.

4. For what might we use multi-character input?

5. For what might we use single-character input?

Part-3

1. How might the flow of execution be affected by a conditional branch?

2. What part of an if/else control structure determines which sequence of blocks is executed?

3. The two different types of input are single-character input and _________ input.

4. Asking for a name is an example of what kind of input.

5. The expression in the predicate part of an if/else structure evaluates to a _____ or ______ value?

6. What part of the structure would execute if the predicate value was false?

Part-4

1. The expression in the predicate part of an if/else structure evaluates to what kind of value.

2. What part of the structure would execute if the predicate value was true.

3. In your own words, what does a loop do?

4. One type of single-character input can be used to start a script, while the other can be used ______ the script. We moved this question to session 4 when we introduce the concept of loops.

5. If a certain block or number of blocks needed to be executed several times, what control structure would you use?

6. If a loop executes 5 times and there was a block inside that moved the sprite 3 steps, how many steps would it move in total?

Part-5

1. What is useful about loops?

2. Once variables contain a value, can that value be changed?

3. Can a variable contain a number, then later in the program, contain words?

4. If so, could this be a problem?

5. If there are two loops, the outer executes 5 times, the inner executes 3 time s. Inside the inner loop, there is a block of code that makes a sprite say "hello world." How many times will the sprite say, "hello world"?

6. Can a variable be used anyplace a number can be used? 

Part-6

1. What three advanced types of Boolean operators do we cover in this session?

2. What is message passing used for in Scratch?

3. Where are Boolean expressions most commonly used?

4. You have a program that has an if/else structure, and two variables, X and Y. The only time you want the alternate block(s) to execute is when both variables equal 10. What Boolean expression could you use in this situation?

5. In your own words, explain the purpose and structure of an array?

6. Explain the difference between the broadcast and broadcast and wait block