streams

2 articles

21 September 2026·7 min read

Java 8 Stream API Interview Questions, With the Output to Prove It

Java 8 stream interview questions answered with output from JDK 8, 21 and 25, including a sorted() that did no work and a parallel reduce wrong every time.

Java

11 September 2026·5 min read

Java Stream API Examples, and Four Ways They Surprise You

Complete stream examples with real output — grouping, flattening, collecting to a map — plus four behaviours that cause bugs not looking like stream bugs.

Java