JavaMadeSoEasy.com (JMSE): Collection - List, Set and Map all properties in tabular form in java

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Hi! In this Collection framework tutorial we will find differences and similarities in most important properties of most widely used Collection framework classes like whether they allows Duplicate elements, maintain insertion order, is Sorted by natural order, allow null elements and Iterator is fail-safe or fail-fast.

List	Duplicate elements	insertion order	Sorted by natural order	synchronized	null elements	Iterator
ArrayList	Yes	Yes			Yes	Iterator & listIterator are Fail-fast
LinkedList	Yes	Yes			Yes	Iterator & listIterator are Fail-fast
Vector	Yes	Yes		Yes	Yes	Iterator & listIterator are Fail-fast
CopyOnWriteArrayList	Yes	Yes		Yes	Yes	Iterator & listIterator are Fail-safe

Set	Duplicate elements	insertion order	Sorted by natural order	synchronized	null elements	Iterator
HashSet					Yes	Fail-fast
CopyOnWriteArraySet				Yes	Yes	Fail-safe
LinkedHashSet		Yes			Yes	Fail-fast
TreeSet			Yes		No	Fail-fast
ConcurrentSkipListSet			Yes	Yes	No	Fail-safe

Map	Duplicate Keys	insertion order of keys	Sorted by natural order of keys	synchronized	null keys or null values	Iterator Map implementations returns 3 iterators > map.keySet().iterator() map.values().iterator() map.entrySet().iterator()
HashMap					one null key and many null values	All are Fail-fast
Hashtable				Yes	No	All are Fail-fast
ConcurrentHashMap				Yes	No	All are Fail-safe
LinkedHashMap		Yes			one null key and many null values	All are Fail-fast
TreeMap			Yes		Null key not allowed, Allow many null values	All are Fail-fast
ConcurrentSkipListMap			Yes	Yes	No	All are Fail-safe