What are custom iterators in Java and how do I create one?

What are custom iterators in Java and how do I create one?

Custom iterators in Java allow you to define your own iteration logic for collections. You can create one by implementing the Iterator interface.

Can you show me a simple example of a custom iterator?

Sure! Here's a basic example:

import java.util.Iterator;

class MyCollection implements Iterable<String> {
    private String[] items = {"A", "B", "C"};

    @Override
    public Iterator<String> iterator() {
        return new MyIterator();
    }

    private class MyIterator implements Iterator<String> {
        private int index = 0;

        @Override
        public boolean hasNext() {
            return index < items.length;
        }

        @Override
        public String next() {
            return items[index++];
        }
    }
}

This code defines a custom collection and its iterator.

What are the benefits of using custom iterators?

Custom iterators provide flexibility in how you traverse collections, allowing for more complex iteration patterns and encapsulation of iteration logic.

Are there any performance considerations I should be aware of?

Yes, while custom iterators can be powerful, they may introduce overhead if not implemented efficiently. Always consider the complexity of your iteration logic.