OnlinePurchaseManager is #2 from the from the 2020 AP Computer Science A Course Description sample problems.
2020 AP CS A Course Description
The sample free response start on PDF page 206 (labeled page 199 at the bottom right). If this link has been redirected to the 2025 Course Description, please let me know as a comment on this page.
Part (a) countElectronicsByMaker method
public int countElectronicsByMaker(String maker)
{
int matches = 0;
for(Gizmo g : purchases)
if(g.isElectronic() && g.getMaker().equals(maker))
matches++;
return matches;
}
Part (b) hasAdjacentEqualPair method
public boolean hasAdjacentEqualPair()
{
for(int i = 1; i < purchases.size(); i++)
if(purchases.get(i - 1).equals(purchases.get(i)))
return true;
return false;
}
Zero or 1 elements are not special cases. The loop will only run if purchases contains at least 2 elements.
Java files with test code
OnlinePurchaseManagerTest.java includes JUnit 5 test code with the examples from the problem. See Running JUnit 5 tests. Gizmo.java includes a working implementation of equals.
Gizmo.java
OnlinePurchaseManager.java
OnlinePurchaseManagerTest.java
2020 AP CS A Course Description Free Response Solutions
Help & comments
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