== Why is this an issue?

The `java.util.Iterator.next()` method must throw a `NoSuchElementException` when there are no more elements in the iteration.
Any other behavior is non-compliant with the API contract and may cause unexpected behavior for users.

=== Noncompliant code example

[source,java,diff-id=1,diff-type=noncompliant]
----
public class MyIterator implements Iterator<String> {
  public String next() {
    if (!hasNext()) {
      return null;
    }
    // ...
  }
}
----

=== Compliant solution

[source,java,diff-id=1,diff-type=compliant]
----
public class MyIterator implements Iterator<String> {
  public String next() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }
    // ...
  }
}
----

== Resources

=== Documentation

* https://docs.oracle.com/javase/7/docs/api/java/util/Iterator.html#next--[Java SE 7 API Specification: Iterator]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Add a "NoSuchElementException" for iteration beyond the end of the collection.


endif::env-github,rspecator-view[]