AP · Analysis & Prediction

2025 AP AP Computer Science A Past Paper: Analysis & Answers

The 2025 AP Computer Science A Free-Response section consisted of four standard 9-point questions spanning 90 minutes. Overall performance averaged 17.86 out of 36 points (49.6%), with Question 2 (Class Design) yielding the highest mean (5.24/9) and Question 4 (2D Arrays) proving most difficult (3.96/9). Key stumbling blocks centered on self-pairing guards in 2D array traversal, two-pointer inward list traversal logic, and instance variable encapsulation.

Updated: 18 Aug 2026

Analysis Sample paper

Difficulty 3.3/5

Total marks

Duration

90 mins

Most tested

Data Collections (ArrayList & 2D Arrays)

Paper breakdown

Section II: Free Response: 36 marks · 90 mins

Top chapters

Unit 4: Data Collections (Course Content) · 18 marksUnit 3: Class Creation (Course Content) · 9 marksUnit 2: Selection and Iteration (Course Content) · 9 marks

Executive Overview & Difficulty Verdict

The 2025 AP Computer Science A FRQ paper maintained the established four-question blueprint, allocating 9 points per question across 90 minutes. With a global exam mean of 3.18 and an average FRQ score of 17.86/36, the paper presented a balanced assessment. Question 2 (Class Design - SignedText) proved most accessible (5.24 mean), driven by straightforward header syntax. Conversely, Question 4 (2D Arrays - SumOrSameGame) saw the lowest average (3.96 mean), largely due to the severe challenge candidates faced when guarding against self-pairing (earned by only 12% of candidates).

Where the Marks Are Won and Lost

Unit 4 (Data Collections): Comprising 50% of the total FRQ marks (18 points across Q3 and Q4), mastering 1D ArrayList and 2D array traversals remains essential. In Q3(b), constructing Match objects by converging from both ends of an ArrayList caused arithmetic off-by-one errors and illegal list modifications. In Q4(b), partial 2D array iteration and compound boolean matching were heavily penalized when students compared an element to itself.
Unit 3 (Class Creation): Q2 awarded easy points for boilerplate class, constructor, and method headers. However, identifying the three distinct signature placement states via String.indexOf and building the modified string accounted for sharp score drops.
Unit 2 (Selection and Iteration): Q1 evaluated method calling and accumulation. Common point losses occurred from invoking methods statically on DogWalkCompany rather than on the instance variable company, and calling walkDogs multiple times inside an accumulation loop.

Examiner Pitfalls & Traps

The Chief Reader report highlighted recurring anti-patterns: (1) Redeclaring parameters or instance variables as local variables inside constructors, (2) using algebraic range checks such as 9 <= i <= 17 rather than logical conjunctions (i >= 9 && i <= 17), (3) using == instead of .equals() for String comparison, and (4) omitting the new operator during object instantiation within data structures.

Strategic Guidance & Predictions

Students preparing for upcoming administrations should drill non-standard traversals (e.g., inwards two-pointer sweeps, bounded 2D sub-grids) and rigorous trace tables on small inputs (3–5 elements). Data Collections and Class Design will continue to anchor 75% of the FRQ mark pool.

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Charts

Marks by chapter

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Question type mix

Compare the mark share of each paper section and question type.

Methods and Control Structures9 marks · 1 questions
Class Design9 marks · 1 questions
Array / ArrayList9 marks · 1 questions
2D Array9 marks · 1 questions

Mark accessibility

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78%within easy or medium reach

easy: 13 marksmedium: 15 markshard: 8 marks

Difficulty trend

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Command word frequency

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Skill weighting

Shows the skill mix this paper tested most heavily.

Study ROI

Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.

Class Structure & Header Syntax

4 marks · Difficulty 1.5 · recurrence 100%

Iteration & Accumulation Algorithms

5 marks · Difficulty 2.2 · recurrence 100%

ArrayList Traversal & Object Population

9 marks · Difficulty 3.4 · recurrence 100%

2D Array Nested Loops & Conditional Grid Search

9 marks · Difficulty 3.9 · recurrence 100%

String Parsing & Substring Index Logic

5 marks · Difficulty 3.6 · recurrence 95%

Time vs marks

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marksmins

Next-year prediction

Topics worth watching next year, with the reason shown directly below each bar.

ArrayList Filtering and Element Removal92%

The 2025 Q3 focused on pairing without list mutation; standard backward-traversal removal or iterator-based filtering is overdue for testing.

2D Array Row/Column Matrix Transformations88%

2D arrays consistently command 9 points every year. Expect row-major or column-major aggregations in the next cycle.

Class Inheritance and Polymorphic Hierarchies15%

Inheritance has been formally phased out of the FRQ specification under the updated CED, focusing Q2 purely on standalone class creation.

Cumulative marks ladder

The line is your running mark total question by question; dashed lines are the estimated grade cut-offs. See which question the line crosses your target grade at, so you know how far you must answer cleanly and which questions decide a band.

Topic-year heatmap

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May 2023

May 2024

May 2025

Unit 4: Data Collections (Course Content)

Unit 3: Class Creation (Course Content)

Unit 2: Selection and Iteration (Course Content)

Examiner insights

Official report

Common pitfalls

Failing to guard against pairing an element with itself in 2D array search algorithms (e.g. comparing puzzle[r][c] with puzzle[row][col] without ensuring (r != row || c != col)).
Calling instance methods statically on the class name (DogWalkCompany.updateDogs(...)) rather than through the instance variable (company.updateDogs(...)).
Calling a state-modifying method multiple times inside a loop iteration instead of capturing the result in a local variable.
Modifying or removing elements from a persistent ArrayList parameter or instance variable when solving a subset problem, violating postconditions.

Misconceptions

Believing that algebraic compound comparisons like '9 <= hour <= 17' are valid Java syntax instead of using logical '&&'.
Assuming '==' can compare String values or empty string checks rather than using 'equals()' or checking string length.
Confusing ArrayList '.get(i)' with array bracket notation '[i]', or attempting to call '.set()' / '.remove()' on 2D arrays.
Assuming casting to int binds after arithmetic operations, e.g. writing '(int) Math.random() * 9 + 1' which evaluates to 1 every time.

Where marks are lost

Question 4 Point 6 (Handle special self-pairing case): Only 12% of candidates earned this mark, the lowest in the paper.
Question 3 Point 9 (Populate match result list algorithmically without bounds errors): Earned by only 19% of candidates due to off-by-one errors when traversing inward from both ends.
Question 2 Point 8 & 9 (Distinguish 3 substring cases and return revised string): Earned by only ~33% of candidates due to flawed indexOf handling and incorrect substring slice indices.
Question 1 Point 1 (Calling instance methods on company): Earned by only 27% because candidates omitted the instance variable target.

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