Java 1.2 introduced the collection classes that we all know and love, ... Note the difference between the passive iterator in Listing 4 and the active iterator in the previous three listings.

Using Java collection you can perform all the operations on the data like searching, sorting, inserting, manipulation, ... LinkedList is way too different than the ArrayLists.

One of the nasty little traps a Java developer can run into occurs when Collection.contains(Object) is not used with appropriate understanding. I demonstrate this potential trap in this post.