One road per run

Computing · Programming · ages 14-16

Name ______________________ Date ____________

An else branch runs when no test above it is true.
Circle one: True False
The temperature is 20. The program runs: if temperature < 32, print a snow jacket warning. What prints?
- The snow jacket warning
- Nothing at all
- An error message
How many branches run in one pass through a chain?
- All of them
- None of them
- Exactly one
A grade chain tests A at 90, B at 70, else Fail. The mark is 82. What prints?
- Fail
- A
- B
A program labels a number positive, negative or neutral with a chain. The number is -5. What prints?
- positive
- negative
- neutral
Why must the A test sit above the B test in a grade chain?
- The program crashes otherwise
- A mark like 95 would match the lower test first and stop
- Marks would print twice
A whole if and else only sets ok to true when users > 100. Which line replaces it?
- ok = users + 100
- ok = users > 100
- ok stays empty
A chain tests mark >= 70 before mark >= 90, and a 95 prints B. What is the fix?
- Test the highest boundary first
- Delete the else
- Swap print for input

Answer key

For grown-ups. Fold this page away before handing over the rest.

True · else is the catcher for everything the tests above missed.
The snow jacket warning · 20 is below 32, so the if test is true and its block runs.
Exactly one · One road per run: the first true branch, or the else.
B · 82 misses A, matches B, and the chain stops there.
negative · -5 fails the above-zero test and passes the below-zero test.
A mark like 95 would match the lower test first and stop · The chain stops at the first match, so a loose test on top steals strong marks.
ok = users > 100 · The test itself produces the Boolean, so store it directly.
Test the highest boundary first · Order decides priority, so the strictest test must come first.