Meaningless Drivel is fun!
The moose likes Performance and the fly likes collection.size() vs. array.length Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of REST with Spring (video course) this week in the Spring forum!
JavaRanch » Java Forums » Java » Performance
Bookmark "collection.size() vs. array.length" Watch "collection.size() vs. array.length" New topic

collection.size() vs. array.length

paul wheaton

Joined: Dec 14, 1998
Posts: 20914

In the article at the advantages of not having collection.size() used in the for loop are pointed out. Would this apply equally to array.length?

permaculture Wood Burning Stoves 2.0 - 4-DVD set
Jack Shirazi
Ranch Hand

Joined: Oct 26, 2000
Posts: 96
No. Java arrays (e.g. char[], Object[], not collection objects) cannot change size. So the value is a constant for any one array, and the loop has a constant value to compare against. The problem with collection.size() is that it makes a method call for every iteration of the loop.
It is sorta covered in the JavaRanch Style Guide.
subject: collection.size() vs. array.length
It's not a secret anymore!