Difference between HashSet and Linkedhash set in java?

Answer 1

The only difference is that the LinkedHashSet maintains the order of the items added to the Set. It does this by maintaining a doubly linked list containing the hash and the original order of the items. According to Sun, the LinkedHashSet should run nearly as fast as the HashSet.

LinkedHashSet A LinkedHashSet is an ordered version of HashSet that

maintains a doubly-linked List across all elements. Use this class instead of HashSet

when you care about the iteration order. When you iterate through a HashSet the

order is unpredictable, while a LinkedHashSet lets you iterate through the elements

in the order in which they were inserted.

HashSet A HashSet is an unsorted, unordered Set. It uses the hashcode

of the object being inserted, so the more efficient your hashCode() implementation

the better access performance you'll get. Use this class when you want a collection

with no duplicates and you don't care about order when you iterate through it.

Answer 2

HashSet

A HashSet is an unsorted, unordered Set. It uses the hashcode of the object being inserted, so the more efficient your hashCode() implementation the better access performance you'll get. Use this class when you want a collection with no duplicates and you don't care about order when you iterate through it.

LinkedHashSet

A LinkedHashSet is an ordered version of HashSet that maintains a doubly-linked List across all elements. Use this class instead of HashSet when you care about the iteration order. When you iterate through a HashSet the order is unpredictable, while a LinkedHashSet lets you iterate through the elements in the order in which they were inserted.