Why is it so

[Mohit Agarwal]

Hi,

According to Sun Java Tutorial,

Use Iterator instead of the for-each construct when you need to:
Iterate over multiple collections in parallel.

Whats the benefit in case we go with the iterator?

Please provide your inputs on this..

Thanks,
Mohit.

[Srinivas Kalvala]

Hello,

The Advantage with iterator is you can get list of objects irrespective of the data structure. if you use for loop then you have to write a seperate for loop for data structure.

Do one thing ...

Search with following Key word in Google:

Iterator Design Pattern

or

http://www.google.co.in/search?hl=en&q=Iterator+Design+pattern&meta=

[Ernest Friedman-Hill]

I don't think that answers the question at all.

The answer is that when using "for/each", you don't actually have access to the Iterator; the loop construct looks directly at the collection or array itself. So let's say you need to do something like this:

int[] numbers = new int[10];
String[] strings = new String[10];
 
for (int i=0; i<10; ++i) {
    numbers[i] = i;
    strings[i] = String.valueOf(i);
}

Do you see how we're using the loop counter to access two different arrays? You can't do that with a single for/each loop; you'd have to write two loops. Therefore, don't use for/each when you need to iterate over multiple collections -- because you can't!

[Srinivas Kalvala]

You are Right,

But my intention was, to make him think about the Iterator pattern so that he can get more ...