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Until now, Java Collections had a gap:
❌ Getting first/last element → inconsistent
❌ Reverse iteration → messy
❌ LinkedHashSet last element? → nearly impossible
Java 21 introduced SequencedCollection, SequencedSet & SequencedMap:
✅ Uniform APIs (getFirst(), getLast(), reversed())
✅ Works across List, Deque, LinkedHashSet, LinkedHashMap
✅ Reverse iteration is finally easy!
✅ You can even reposition elements in sets/maps
A small change, but a huge improvement for everyday code.
👉 Check the carousel for details and examples.
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