hashCode() used for searching is right?

[nagaraj raja]

hai i am thinking Hashtable,HashMap,HashSet are implemented hashing mechanisem ie it will generate hashCode this is useful searching the elements in a collection this is my openion os hashing is it right??

[marc weber]

Yes, the primary benefit of hashCode is fast lookup.

Imagine a library with numerous rows of bookshelves. If you're looking for a particular book, it would be a lot faster if you knew what particular row of shelves to look in, rather than searching through the entire library. Of course, when you've found the correct shelves (indicated by hashCode), there might be other books on those shelves (because different objects might return the same hashCode), but you've narrowed your search to a much smaller region.

[Philip Heller]

You're right, hash codes are used for efficient storage in collections. But as for sorting, only collections whose names begin with "Tree" sort their elements. See Chapter 8 of "Complete Java 2 Certification" for more.

-- Phil

[Arulkumar Gopalan]

boolean equals(Object o) method also uses the hashing mechanism to compare object references.