"Java_ Set frame Set" HashSet, Linkedhashset, treeset use differences

HashSet: A hash table stores information by using a mechanism called hashing, and the elements are not stored in a particular order;

Linkedhashset: maintains a linked table of the collection in the order in which the elements are inserted, allowing iterations in the collection in the order in which they are inserted;

TreeSet: Provides an implementation that uses a tree structure to store a set interface, where objects are stored in ascending order, and the time to access and traverse is fast.

Sample code::

1  PackageCom.test2;2 3 ImportJava.util.HashSet;4 ImportJava.util.Iterator;5 ImportJava.util.LinkedHashSet;6 Importjava.util.List;7 ImportJava.util.Set;8 ImportJava.util.TreeSet;9 Ten  Public classset { One  A      Public Static voidLinkedhashset () { -         //Maintains a linked table of the collection in the order in which the elements are inserted, allowing iterations in the collection in the order in which they are inserted; -System.out.println ("Here is Linkedhashset:"); theSet<string> set =NewLinkedhashset<string>(); -Set.add ("AAA"); -Set.add ("D"); -Set.add ("Z"); +Set.add ("AAA"); -Set.add ("BBB"); +          for(Iterator<string> iter =set.iterator (); Iter.hasnext ();) { AString str =Iter.next (); at System.out.println (str); -         } -  -     } -  -      Public Static voidTreeSet () { in         //provides an implementation that uses a tree structure to store a set interface, where objects are stored in ascending order, and the time to access and traverse is fast.  -System.out.println ("Here is TreeSet:"); toSet<string> set =NewTreeset<string>(); +Set.add ("AAA"); -Set.add ("D"); theSet.add ("Z"); *Set.add ("AAA"); $Set.add ("BBB");Panax Notoginseng          for(Iterator<string> iter =set.iterator (); Iter.hasnext ();) { -String str =Iter.next (); the System.out.println (str); +         } A  the     } +  -      Public Static voidHashSet () { $         //A hash table stores information by using a mechanism called hashing, and elements are not stored in a particular order $System.out.println ("Here is HashSet:"); -Set<string> set =NewHashset<string>(); -Set.add ("AAA"); theSet.add ("D"); -Set.add ("Z");WuyiSet.add ("AAA"); theSet.add ("BBB"); -          for(Iterator<string> iter =set.iterator (); Iter.hasnext ();) { WuString str =Iter.next (); - System.out.println (str); About         } $  -     } -  -      Public Static voidMain (string[] args) { A Linkedhashset (); + hashset (); the TreeSet (); -  $     } the  the}

Result output:

Here is Linkedhashset:
Aaa
D
Z
Bbb
Here is HashSet:
Aaa
Bbb
D
Z
Here is TreeSet:
Aaa
Bbb
D
Z

"Java_ Set frame Set" HashSet, Linkedhashset, treeset use differences