What are the benefits of using an iterator in Java

Question

I was browsing over the following code example:

public class GenericTest {
  public static void main (String[] args) {
    ArrayList<String> myList = new ArrayList<String>();
    String s1 = "one";
    String s2 = "two";
    String s3 = "three";

    myList.add(s1); myList.add(s2); myList.add(s3);

    Iterator<String> itr = myList.iterator();
    String st;

    while (itr.hasNext()) {
      st = itr.next();
      System.out.println(st);
    }
  }
}

I'm wondering what are the benefits of using an implementation of the Iterator interface instead of using a plain-old for-each loop?

 for (String str : myList) {
   System.out.println(str);
 }

If this example is not relevant, what would be a good situation when we should use the Iterator?

Answer 1

Basically, foreach loop is a shortcut for the most common use of an iterator. This is, iterate through all elements. But there are some differences:

• You can iterate through an array using foreach loop directly
• You can remove objects using an iterator, but you can't do it with a foreach loop
• Sometimes is useful to pass an iterator to a function (specially recursive ones)