Is it possible to use a custom object in a for-each loop as an iteration element?

Yes, a custom object can be used in a for-each loop if it implements the Iterable interface or is an array.

For this, the class must implement the iterator() method, which returns an object of type Iterator. For example:

import java.util.Iterator;

class MyCollection implements Iterable<String> {
    private String[] data = {"one", "two", "three"};

    @Override
    public Iterator<String> iterator() {
        return new Iterator<String>() {
            private int index = 0;

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

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

public class Main {
    public static void main(String[] args) {
        MyCollection collection = new MyCollection();
        for (String item : collection) {
            System.out.println(item);
        }
    }
}

In this example, MyCollection can be used in a for-each loop because it implements Iterable.