// collectiontopics/FailFast.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Demonstrates the "fail-fast" behavior
import java.util.*;

public class FailFast {
  public static void main(String[] args) {
    Collection<String> c = new ArrayList<>();
    Iterator<String> it = c.iterator();
    c.add("An object");
    try {
      String s = it.next();
    } catch(ConcurrentModificationException e) {
      System.out.println(e);
    }
  }
}
/* Output:
java.util.ConcurrentModificationException
*/