Big Idea 3 · Topic 3.12 · Exercise 1
Trace the Call
25 minutes
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Q1 · 3 points on the handout
In your own words, explain what 'flow of control is returned to the point immediately following where the procedure was called' means, using the idea of a detour or round trip. Why is it useful that control comes back to exactly that spot?
Q2 · 3 points on the handout
A classmate says, 'To call showItem I have to name my arguments item and price, or the computer won't know where they go.' Correct this precisely, and give an example call using arguments that are NOT named item or price.
Q3 · 2 points on the handout
ENRICHMENT: Suppose line 4 read count <- INPUT() instead, and then total <- costFor(count). Explain how INPUT() and costFor are ALIKE in one important way, and predict how the output could differ from one run to the next.
Q4 · 0 points on the handout
Next step: you traced these calls by hand. Now head to the Topic 3.12 page and type and run the harder versions, where the computer checks your output for you.
No graded check on this page yetNot recorded
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Hand this in the way your teacher asked for it. Topic 1.1 has its graded check today, and the rest follow.