AP Computer Science A Exam Guide and Review

Review the units in their published order

The percentages below are ranges for the multiple-choice section, not shares of the whole exam and not promised question counts. Use them to balance practice, then keep every unit in mixed review because its Java decisions support later work.

Three hours split evenly between reading and writing code

The multiple-choice section rewards precise tracing and rule-based elimination. Every free-response question assesses Develop Code, so a response must turn the stated requirements into complete Java rather than only predict output.

Official exam information (as of 2026-08-12): College Board AP Computer Science A exam page. Check the official page again before test day because administration details can change.

Find the earliest complete run

public class Main {
  static int firstRun(boolean[] open, int need) {
    int run = 0;
    for (int i = 0; i < open.length; i++) {
      run = open[i] ? run + 1 : 0;
      if (run == need) return i - need + 1;
    }
    return -1;
  }
  public static void main(String[] args) {
    boolean[] a = {false, true, true, true, false};
    System.out.println(firstRun(a, 3));
  }
}

The loop stores the length of the current consecutive run. A false element resets that state. When the run first reaches the required length, the current index is the end of the run, so subtracting the needed length and adding one converts the end position to the starting position. The failure value appears only after the complete scan.

An empty array executes the loop zero times and returns -1. A run that finishes at the final array position still succeeds. The conversion is end index - needed length + 1, not end index - needed length. The method reads the supplied array without replacing it or changing its elements.

This table is an independently written practice checklist, not an official AP scoring guide. Use it to point to the exact code that supplies each behavior, then test the method with an empty array, a run at the beginning, a run at the end, and an input with no complete run.

Fourteen terms to use precisely

These definitions come from the book’s unit glossary pages. Connect each word to code: identify the receiver of a call, the lifetime of state, the legal index interval, and whether an assignment copies a primitive value or creates another reference to the same object.

object

A class instance that holds state and can receive method calls.

method

Named behavior called with a receiver or through a class when static.

receiver

The object written before the dot in an instance-method call.

argument

A value or expression supplied to a method parameter.

return value

The result sent from a non-void method to its caller.

String

An object representing a sequence of characters.

substring

A contiguous portion selected with an inclusive start and exclusive end.

instance state

Field values belonging to one object at a particular time.

reference

A value that identifies an object rather than copying its contents.

alias

A second variable that refers to the same mutable object.

selection

A condition-controlled choice among execution paths.

iteration

Repeated execution while a loop condition permits it.

array

A fixed-length indexed container accessed with brackets.

ArrayList

A resizable indexed list accessed through methods such as get and add.

What to expect and how to use this guide

Use four passes to turn tracing into reliable code

Pass 1: map the exam and units. Learn the two 90-minute sections, then use the published multiple-choice ranges to balance the four units. Keep a short mixed set in every session so earlier object and control-flow skills remain available when you reach classes and collections.

Pass 2: trace before you write. For every short program, record the receiver, arguments, returned value, side effects, loop interval, and each state update. Stop at the moment the question asks about; an extra imagined iteration is a common reason a plausible answer becomes wrong.

Pass 3: build complete responses. Translate the prompt into inputs, persistent state, required mutations, and output. Write the requested class or method in full, then test empty data, first and final positions, an absent target, consecutive matches, repeated calls, and shared references.

Pass 4: audit with the real exam tools. Practice locating a method signature on the Java Quick Reference, but also practice without looking up language rules that the sheet does not teach. Finish timed work by checking syntax, bounds, state, and return behavior in that order.

Official course information (as of 2026-08-12): College Board AP Computer Science A course page.