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container, Iterators , Collection ?

Siva kandasamy
Ranch Hand

Joined: Dec 31, 2002
Posts: 139
Hi there,
a) Can you explain what is

1. container
Is array is also a container ?

2. Iterators
Why Iterators ?

3. Collection
4. Collections
What is the relation between Collection and Collections.

5. Comparable
6. Comparator
What is the relation between Comparable and Comparator.

nikos sokaf
Ranch Hand

Joined: May 01, 2004
Posts: 57
The informations you need you will find on tutorials...

I suggest you to check out all the java.util.* package.
Dirk Schreckmann

Joined: Dec 10, 2001
Posts: 7023
Moving this to the Intermediate forum..

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Warren Dew
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Joined: Mar 04, 2004
Posts: 1332
2. While iterators don't always save much typing over manual iteration, using them tends to result in a fewer bugs, and thus less debugging time. They also tend to be a bit more legible, once you get used to them.

3&4 A Collection is just that - a collection of objects. The Collections class provides useful static methods for use with the various Collection subclasses.

5&6 A Comparator is a thing that does the comparing. Something that implements Comparable is something that gets compared.

A Comparator is typically written to compare two things that aren't normally compared, or to compare them in a different way than normal. Things that implement Comparable are expected to be compared, and can be compared without writing an explicit Comparator class.
Herb Schildt
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Joined: Oct 01, 2003
Posts: 253

As a point of interest, with the new Java 2, v1.5 (tiger), Java supports a "for-each" style of for loop that automatically iterates over a collection. Its use simplifies the code that cycles through a collection. Given your current line of questioning, you might want to check it out.

For my latest books on Java, including Introducing JavaFX 8 Programming, see
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