why to use 'iterator' to loop thru an ArrayList. It can be done without Iterator also right?

why use 'iterator' to loop thru an ArrayList. It can be done without Iterator also right?
so the benefits of using iterator to loop thru an ArrayList

import java.util.ArrayList;
import java.util.Iterator;

 public class IteratorDemo {
  public static void main(String[] args) {

    // Make a collection
    ArrayList<String> cars = new ArrayList<String>();
    cars.add("Volvo");
    cars.add("BMW");
    cars.add("Ford");
    cars.add("Mazda");

    // Get the iterator
    //Iterator<String> it = cars.iterator();

    // Looping without Iterator
    for(int i=0;i<4;i++) {
        //System.out.println(it.next());

        System.out.println(cars.get(i));
    }
  }
 }

Sometimes you just don't need the index so it is easier. But try doing this using an indexed for loop. It can be done, but not as easily.

List<Integer> list = new ArrayList<>(
				List.of(1, 2, 2, 3, 4, 4, 5, 6, 6, 7, 8, 8, 9, 10, 10));
Iterator<Integer> it = list.iterator();
while (it.hasNext()) {
   // if even, remove it.
   if (it.next() % 2 == 0) {
      it.remove();
   }
}
System.out.println(list);

Prints

[1, 3, 5, 7, 9]

Using an interator allows you to modify lists that might otherwise trigger a concurrent modification exception.

Also, assume you had a class implementation that generated primes or fibonacci numbers. You could do this to grab them individually.

Fibonacci fib = new Fibonacci(0, 1, 10);
for (long i : fib) {
	System.out.print(i + " ");
}

Prints

0 1 1 2 3 5 8 13 21 34 

The Fibonacci class

class Fibonacci implements Iterable<Long> {
	public long start;
	public long next;
	public long count;
	
	public Fibonacci(int start, int next, int count) {
		this.start = start;
		this.next = next;
	    this.count = count;
	}
	
	private class MyIterator implements Iterator<Long> {
		int n = 0;
		
		public boolean hasNext() {
			return n < count;
		}
		
		public Long next() {
			n++;
			long ret = start;
			start = start + next;
		    next = ret;
			return ret;
		}
	}
	
	public Iterator<Long> iterator() {
		return new MyIterator();
	}
}

By implementing Iterable in the class I can use the foreach construct to get elements of the class.

You probably don't have benefit of using it directly. But the iterator is used by for example the forEach.

Just to loop through it you don't need an iterator, a for loop will suffice. If you need to modify the list then you need it to avoid ConcurrentModificationException.