.. _empty:

=====
empty
===== 

Whether a value is the empty sequence

Description
~~~~~~~~~~~
The fn:empty function checks whether sequence is empty, meaning that it contains 
zero items. A sequence is not considered empty just because it only contains a 
zero-length string, the value 0, or an element with empty content.

It is often unnecessary to call the fn:empty function because sequences are 
automatically converted to their effective boolean value where a boolean value 
is expected

.. list-table::
   :widths: 40 60
   :header-rows: 1

   * - **Parameters**
     - **Description**
   * - arg:string()
     - 

Examples
~~~~~~~~
.. list-table::
   :widths: 25 25 50
   :header-rows: 1

   * - **XPath**
     - **Results**
     - **Explanation**
   * - empty( ('a', 'b', 'c') )
     - false
     - 
   * - empty( () )
     - true
     - 
   * - empty(0)
     - false
     - 
   * - empty($in-xml/a)
     - false
     - 
   * - empty($in-xml/b)
     - false
     - 
   * - empty($in-xml/c)
     - false
     - 
   * - empty($in-xml/foo)
     - true
     - Or a static error, if static typing is in effect and foo is not an allowed child.
.. list-table::
   :widths: 50 50
   :header-rows: 1

   * - **XPath**
     - **Results**
   * - empty( ('a', 'b', 'c') )
     - false
   * - empty( () )
     - true
   * - empty(0)
     - false
   * - empty($in-xml/a)
     - false
   * - empty($in-xml/b)
     - false
   * - empty($in-xml/c)
     - false
   * - empty($in-xml/foo)
     - true

See Also
~~~~~~~~

.. toctree::
   :titlesonly:
   :glob:

* :ref:`exists`.
* :ref:`functx_if-empty`.
* :ref:`functx_if-absent`.
* :ref:`functx_all-whitespace`.