== Why is this an issue?

By contract, any implementation of the `java.util.Iterator.next()` method should throw a `NoSuchElementException` exception when the iteration has no more elements.
Any other behavior when the iteration is done could lead to unexpected behavior for users of this `Iterator`.


=== Noncompliant code example

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


=== Compliant solution

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

== Resources

* https://docs.oracle.com/javase/8/docs/api/java/util/Iterator.html#next--[JavaDoc 8 - java.util.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[]