==============================
MongoDB\\ChangeStream::valid()
==============================

.. default-domain:: mongodb

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Definition
----------

.. phpmethod:: MongoDB\\ChangeStream::valid()

   Returns whether there is a current event in the change stream.

   .. code-block:: php

      function valid(): boolean

   When manually iterating the change stream using
   :php:`Iterator </manual/en/class.iterator.php>` methods, this method should
   be used to determine if :phpmethod:`MongoDB\\ChangeStream::current()` and
   :phpmethod:`MongoDB\\ChangeStream::key()` can be called.

Return Values
-------------

A boolean indicating whether there is a current event in the change stream.

See Also
--------

- :phpmethod:`MongoDB\\Client::watch()`
- :phpmethod:`MongoDB\\Collection::watch()`
- :phpmethod:`MongoDB\\Database::watch()`
- :php:`Iterator::valid() <iterator.valid>`
- :ref:`Tailable Cursor Iteration <php-tailable-cursor>`
- :manual:`Change Streams </changeStreams>` documentation in the MongoDB manual
