The AP Computer Science A course is built from a list of specific ideas, and the exam can ask about any of them. The official list is written for teachers, so it can be hard to read when you're the one learning the material. This study guide explains every idea in plain language, one page per unit.

How the codes work

Every idea has a code, like 1.2.B.1:

• 1 is the unit.
• 1.2 is the topic within that unit.
• 1.2.B is the learning objective, the skill you should be able to show.
• 1.2.B.1 is one specific idea behind that skill.

When you check a practice question or finish a practice test, the codes in the table link straight to the matching idea here, so you can read about exactly what you missed.

These explanations are written in our own words. For the exact official wording, see the AP Computer Science A Course and Exam Description.

The units

• Unit 1: Using Objects and Methods: 15 topics, 76 ideas. About 15–25% of the multiple-choice section.
• Unit 2: Selection and Iteration: 12 topics, 34 ideas. About 25–35% of the multiple-choice section.
• Unit 3: Class Creation: 9 topics, 42 ideas. About 10–18% of the multiple-choice section.
• Unit 4: Data Collections: 17 topics, 71 ideas. About 30–40% of the multiple-choice section.