Quiz Show I

Review — where we got to 5 min

The Maze Escape is finished. Two things come back today.

• A score variable, and change [score v] by (1), from the catching game in Topic 1.12.
• broadcast [verse v] as a cue, from the Music Video.

Quick-fire

Every game so far reads the keyboard or the mouse. How would a project ask you a question and wait for a proper answer?

Today’s Topic 3 min

• ask [What is your name?] and wait — the project waits for you
• (answer) — where your typing goes
• <() = ()> — checking whether the answer is right
• One script per question, joined up with broadcasts

Learning outcome

By the end of this lesson you will be able to:

1. Ask a question and use what the player types.
2. Say one thing when they are right and a different thing when they are wrong.
3. Run three questions in a row and read the score out at the end.

Learnt — ask, answer, check 28 min

1 · The block that waits for a person

Every block so far has run and finished. This one does not. It puts a white box at the bottom of the Stage and waits.

1. Click Sensing. It is the light blue drawer.
2. Drag out ask [What's your name?] and wait.
3. Click the white box in the block and type your own question.
4. Press the green flag.
5. A box appears at the bottom of the Stage. Type something and press Enter.

What you typed did not disappear. Scratch kept it in a block called (answer), two blocks below the ask block in the same drawer.

1. Tick the box beside (answer) in the palette.
2. A small box appears on the Stage showing what you last typed.
3. Run it again and type something different. The box changes.

Putting the answer inside a sentence

say (answer) says only the word. To make a sentence, glue two pieces together with join [apple ] [banana] from Operators.

when flag clicked
ask [What is your name?] and wait
say (join [Hello, ] (answer)) for (3) seconds
            

2 · Right or wrong

A quiz has to know the right answer. You compare what they typed with what it should be, using the <() = ()> block from Operators.

1. Drag if <> then with its else half out of Control.
2. Drop <() = ()> into its diamond.
3. Drag (answer) into the left side.
4. Type the right answer into the right side.
5. Put a happy say block in the top gap and a kind one in the bottom gap.

when flag clicked
ask [How many legs has a spider?] and wait
if <(answer) = [8]> then
  say [Correct!] for (2) seconds
else
  say [No. A spider has 8.] for (2) seconds
end
            

3 · Three questions without a giant stack

Three questions in one stack is twenty blocks. Nobody can read that. Give every question its own little script, and let each one call the next.

when I receive [question 1 v]
ask [How many legs has a spider?] and wait
if <(answer) = [8]> then
  change [score v] by (1)
end
broadcast [question 2 v]
            

The last question broadcasts result instead, and one more script reads the score out.

when I receive [result v]
say (join [You scored ] (join (score) [ out of 3.])) for (4) seconds
            

Basic — build the show 25 min

Build one question and test it. Only then build the second one.

Step 1 — the room

1. New project, cat deleted.
2. Choose the Theater backdrop.
3. Add a person sprite as the host. Avery works well.
4. Add a Microphone sprite beside them if you like.

Step 2 — the score

1. In Variables, make a variable called score.
2. Leave its box ticked so it shows on the Stage.
3. On the host, start a stack: when flag clicked, then set [score v] to (0).

Step 3 — the first question

1. Add broadcast [question 1 v] under the set block. Scratch will ask you for a new message name.
2. Start a new stack with when I receive [question 1 v].
3. Put the ask block, the if block and the change-score block in it.
4. Test it. Answer right, and watch the score go to 1. Answer wrong, and it stays 0.

Step 4 — the other two

1. Right-click your question script and choose Duplicate. Twice.
2. Change the hat on each copy to question 2 and question 3.
3. Change the question and the right answer in each one.
4. Put broadcast [question 2 v] at the bottom of the first one, and question 3 at the bottom of the second.
5. Test after every single change.

Step 5 — the result

1. At the bottom of question 3, broadcast result.
2. Build the when I receive [result v] script with the joined sentence in it.
3. Play the whole show twice. Once perfectly, once badly.

Your own three questions

Throw my questions away. Write three of your own about anything you like.

• Three questions, all yours.
• Each one adds a point when it is right.
• The result at the end still reads out the correct score.

A question with a word answer

All three of your questions probably want a number. Add one whose answer is a word, and find out how fussy Scratch is about it.

• One question whose right answer is a word.
• You have tried it with a capital letter and without.
• You have tried it with a space on the end.
• You can say which of those Scratch accepts.

Say what the right answer was

“Wrong” teaches nobody anything. Make every wrong answer tell the player what they should have said.

• All three questions have an else branch.
• Each else branch names the correct answer.
• It sounds kind, not cross.

A host who remembers your name

Ask the player their name before the first question, and use it again on the result card at the end.

• The host greets the player by name before question 1.
• The result card says the player’s name and their score.
• It still works if the next player types a different name.

when flag clicked
ask [What is your name?] and wait
set [player v] to (answer)
say (join [Good luck, ] (player)) for (2) seconds
broadcast [question 1 v]
            

when I receive [result v]
say (join (player) (join [ scored ] (score))) for (4) seconds
            

Summary 4 min

Today the project stopped talking at the player and started listening to them.

1. ask [] and wait stops everything until a person types.
2. What they typed is waiting in (answer).
3. <() = ()> inside an if / else tells right from wrong.
4. One script per question, joined up with broadcasts, stays readable.

Ask

A block that stops the project and waits for the player to type something.

Answer

Where Scratch keeps the last thing the player typed. Only the last one.

Join

Glues two pieces of writing together to make one sentence.

Equals

Asks whether two things are the same. The heart of every quiz.

Next lesson: three lives, a pass mark, and a show that can end before the questions run out.