Generics & the Type System
Type erasure, wildcards and PECS, variance, and designing APIs that are both flexible and safe.
- 1✓
What is type erasure? What are its practical consequences, and why did Java choose it?
senior - 2✓
Explain PECS (producer extends, consumer super). When do you use wildcards vs type parameters?
senior - 3✓
Why are Java arrays covariant but generics invariant? What is heap pollution?
staff - 4✓
Design question: how do you use bounded and recursive type parameters to build safe, fluent APIs?
architect - 5✓
How does type inference work (diamond, var, generic methods)? Where does it bite back?
senior