StudyToCert

All certifications / OCP Java / Lessons

Oracle Certified Professional: Java SE Developer 1Z0-831 (Java SE 25) · Domain 5: Working with arrays and collections

Map methods: merge, computeIfAbsent, getOrDefault, putIfAbsent

▶ Watch the overview video

Last reviewed September 25, 2026 · Leer en español

Beyond put and get, the Map interface has default methods that handle common patterns in a single call: counting, grouping and supplying fallbacks. The exam tests their exact return values and how they treat missing keys and null values, so learn each one's rule precisely.

Free account

Keep reading for free

Create a free StudyToCert account to read the rest of this lesson: 6 more sections, 4 key terms, a real-world example, an exam tip and self-check questions. Every lesson, lab and practice test is free with an account.

Sign up free Log in

Study OCP Java for free
A week-by-week plan with every lesson, quizzes, checkpoint tests, a practice exam and hands-on labs.
Open the OCP Java study plan