.. _functx_substring-before-match:

=============================
functx:substring-before-match
============================= 

The substring before the last text that matches a regex

Description
~~~~~~~~~~~
The functx:substring-before-match function returns the part of $arg that appears 
before the first match of $regex. If $arg does not match $regex, the entire $arg 
is returned. If $arg is the empty sequence, a zero-length string is returned.

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

   * - **Parameters**
     - **Description**
   * - arg:string()
     - the string to substring
   * - regex:string()
     - the regular expression

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

   * - **XPath**
     - **Results**
   * - functx:substring-before-match('abc-def-ghi', '[dg]')
     - abc-
   * - functx:substring-before-match('abc-def-ghi', '[dg]')functx:substring-before-match('abcd-abcd', 'bc?')
     - a
   * - functx:substring-before-match('abcd-abcd', 'x')
     - abcd-abcd

See Also
~~~~~~~~

.. toctree::
   :titlesonly:
   :glob:

* :ref:`substring-before`.
* :ref:`functx_substring-after-last-match`.