Keywords: Java HashMap Java Collections Framework fast lookups unordered collection performance thread safety ordered collection

Java ArrayDeque Testing JUnit Unit Tests Data Structures Collections Framework

Map Java HashMap key-value pairs Collections Framework

Enhanced for-each loop Java 5 Streams API lambda expressions Java Collections Framework

TreeSet Java collections framework sorted set Red-Black tree elements unique comparator

Queue Java Queue Interface Java Collections Framework Java Concurrency Java Updates

Java ConcurrentSkipListMap Collections Framework Thread-safe map Sorted map

NavigableMap Java Collections Framework Map Interface Sorted Map TreeMap Key Navigation

TreeSet performance memory usage Java Collections Framework Red-Black tree sorted collection

Java Set HashSet Collections Framework Programming

Queue Java Data Structure Collections Framework

ArrayList Java Collections Framework Resizable Array Dynamic Array Manipulation