ruby · level 1 · unit 4 · lesson 4
- meet it
- guess first
- your turn
- fix it
- nailed it
Tap a green word if you get lost.
meet it
Build bigger questions with , and .
&& means and. It links two conditions and gives true only when both sides are true. A cake needs flour and eggs: if either one is missing, there is no cake.
|| means or. It gives true when at least one side is true, like a lie-in on Saturday or Sunday. ! means not. It flips an answer, so !true is false.
A box holding true or false already counts as a condition. So if !has_eggs reads as: if we do not have eggs.
has_flour = true
has_eggs = false
puts has_flour && has_eggs
puts has_flour || has_eggs
puts !has_eggsWrite a full condition on each side, like day == "Saturday" || day == "Sunday".
guess first
Picnic or not? Make a guess.
Guess before you run it. Wrong guesses are how you learn, and nothing is marked.
raining = false
sunny = true
if sunny && !raining
puts "Picnic in the park!"
end
puts "Have a nice day."your turn
Your turn. Get on the Twister.
The Twister has two rules: you must be 8 or older, and at least 120 cm tall. Choose an age and a height that get you on.
fix it
Since when are crisps healthy? Fix the check.
- Crisps are not an apple or a banana, yet it says healthy. Look at the right side of
||. "banana"on its own is not a question, and Ruby counts it as a yes. So theifalways runs.- Write the box name again:
snack == "apple" || snack == "banana", then press run.
nailed it
you can ask smarter questions now. :D
&&needs both sidestrue.||needs at least one.!flipstruetofalse, andfalsetotrue.- Write a full condition on each side of
&&or||.
new words in your collection
- &&
- ||
- !
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