AP Computer Science A · Computer Science
AP Computer Science A: free lessons and course outline
Java from your first compile to recursion, taught in the four units of the 2025 College Board framework. Fifty-eight lessons follow the CED topic by topic, quote the required content, run every program through a real compiler, and end with six practice items each; every unit ends with ten exam-style multiple-choice questions on a code stimulus, and the free-response section holds eight full FRQ prompts with scoring notes and a canonical nine-point solution.
AP Computer Science A follows the four units of the 2025 College Board framework. Unit 4 (data collections, 30–40%) and Unit 2 (selection and iteration, 25–35%) carry most of the exam's weight, and the four free-response questions come from them in a fixed order: methods and control structures, class design, data analysis with an ArrayList, and a 2D array. Section I is 42 multiple-choice questions in 90 minutes for 55% of the score; Section II is those four free-response questions in 90 minutes for the other 45%, each scored out of 9. The course has 58 lessons: 14 in Unit 1, 14 in Unit 2, 10 in Unit 3 and 20 in Unit 4. Each lesson quotes the CED's required content, shows Java that was compiled and run, traces it step by step, flags what the exam asks in an Exam focus box, and ends with six practice items with answers. Inheritance and overriding are outside the 2025 course, so this course does not teach them, and recursion is taught for tracing only because writing recursive code is also outside the exam. Every unit ends with a ten-question review in the exam's own multiple-choice style, and the FRQ section at the bottom of the outline holds eight prompts, two of each exam type, each with a coding space, the scoring notes, and the canonical solution explained point by point.
- U1Using Objects and Methods15–25%
- U2Selection and Iteration25–35%
- U3Class Creation10–18%
- U4Data Collections30–40%
Every lesson, unit by unit
U1 is free to read below. The other units open with a free month or a paid plan.
U1 Using Objects and Methods 15–25% of the examFREE
- 1.1 Algorithms, programs, and compilers
- 1.2 Variables and data types
- 1.3 Expressions and output
- 1.4 Assignment statements and input
- 1.5 Casting and the range of variables
- 1.6 Compound assignment operators
- 1.7 APIs, libraries, and documenting code
- 1.8 Method signatures
- 1.9 Calling class methods
- 1.10 The Math class
- 1.11 Objects, classes, and constructors
- 1.12 Calling instance methods
- 1.13 Strings: creating and combining
- 1.14 String methods and indexes
U2 Selection and Iteration 25–35% of the exam
- 2.1 Algorithms with selection and repetition
- 2.2 Boolean expressions and relational operators
- 2.3 if statements
- 2.4 Nested if statements and multiway selection
- 2.5 Compound Boolean expressions
- 2.6 Equivalent Boolean expressions
- 2.7 Comparing object references
- 2.8 while loops
- 2.9 for loops
- 2.10 Standard algorithms: divisors, digits, and counting
- 2.11 Standard algorithms: minimum, maximum, sum, and average
- 2.12 Implementing String algorithms
- 2.13 Nested iteration
- 2.14 Informal run-time analysis
U3 Class Creation 10–18% of the exam
- 3.1 Abstraction and program design
- 3.2 Impact of program design
- 3.3 Anatomy of a class
- 3.4 Constructors
- 3.5 Methods: void, non-void, and return
- 3.6 Methods: accessors, mutators, and parameters
- 3.7 Passing and returning object references
- 3.8 Class variables and class methods
- 3.9 Scope and access
- 3.10 The this keyword
U4 Data Collections 30–40% of the exam
- 4.1 Data: ethics, quality, and data sets
- 4.2 Arrays: creating and accessing
- 4.3 Array traversals
- 4.4 Array algorithms: extremes, sums, and counts
- 4.5 Array algorithms: pairs, duplicates, shifts, reversal
- 4.6 Text files
- 4.7 Wrapper classes
- 4.8 ArrayList methods
- 4.9 ArrayList traversals and deleting safely
- 4.10 ArrayList algorithms
- 4.11 Traversing two collections at once
- 4.12 Two-dimensional arrays
- 4.13 Traversing 2D arrays
- 4.14 2D array algorithms
- 4.15 Linear search
- 4.16 Selection sort
- 4.17 Insertion sort
- 4.18 Recursion
- 4.19 Recursive traversal and binary search
- 4.20 Merge sort
Keep going in the full AP Computer Science A course
All of U1 (Using Objects and Methods) is free to everyone, with no account. The course has 58 lessons, each with worked examples and practice problems that come with full solutions. A free account can also start a free month of the whole course, with no card.
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