This is the long-hand form of record Point(int x, int y) {}. The record declaration auto-generates exactly these members: a canonical constructor, accessor methods named after each component (x(), y()), and value-based equals, hashCode, and toString. Records are implicitly final and their components are final, so instances are immutable and safe to share across threads. Use them for DTOs, pair returns, and value objects, but reach for a regular class when you need mutability or inheritance.

Records on JDK 16+ accept a compact constructor (no parameter list) where you can validate or normalize the components before they are assigned to the implicit fields. This snippet shows the same pattern in regular-class form so it runs on JDK 13. You can also add extra instance methods like contains to a record exactly as shown here. Throw IllegalArgumentException for invariant violations so the failure surfaces at construction time rather than later.

Because records (and the equivalent class shown here) generate value-based equals and hashCode, they work as HashMap keys and HashSet members out of the box. This is the killer feature versus a plain class with reference equality: two newly constructed Pair(0, 0) instances hash the same and look up the same entry. On JDK 16+ the Pair class collapses to record Pair(int a, int b) {}. Avoid records as keys only if any component is mutable in a way that affects equality, but records enforce immutability for you, so this rarely happens in practice.