.. _functx_is-a-number:

==================
functx:is-a-number
================== 

Whether a value is a numeric

Description
~~~~~~~~~~~
The functx:is-a-number function returns true if the value is number(can be cast 
to a numeric type) and its not the value NaN. If the argument is the empty 
sequence or a zero-length string, it returns false.

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   :widths: 40 60
   :header-rows: 1

   * - **Parameters**
     - **Description**
   * - value:numeric()
     - the value to test

Examples
~~~~~~~~
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   :header-rows: 1

   * - **XPath**
     - **Results**
   * - functx:is-a-number('123')
     - true
   * - functx:is-a-number(123)
     - true
   * - functx:is-a-number('  123  ')
     - true
   * - functx:is-a-number('')
     - false
   * - functx:is-a-number('123abc')
     - false
   * - functx:is-a-number('NaN')
     - false
   * - functx:is-a-number($in-xml/a)
     - true
   * - functx:is-a-number($in-xml/b)
     - false

See Also
~~~~~~~~

.. toctree::
   :titlesonly:
   :glob:

* :ref:`number`.