.. _functx_index-of-string-first:

============================
functx:index-of-string-first
============================ 

The first position of a substring

Description
~~~~~~~~~~~
The functx:index-of-string-first function returns an integer representing the 
first position of $substring within $arg. If $arg does not contain $substring, 
the empty sequence is returned.

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

   * - **Parameters**
     - **Description**
   * - arg:string()
     - the string
   * - substring:string()
     - the substring to find

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

   * - **XPath**
     - **Results**
   * - functx:index-of-string-first('abcdabcdabcd','abc')
     - 1
   * - functx:index-of-string-first('abcd','abc')
     - 1
   * - functx:index-of-string-first('xxx','abc')
     - ()

See Also
~~~~~~~~

.. toctree::
   :titlesonly:
   :glob:

* :ref:`functx_index-of-string`.
* :ref:`functx_index-of-string-last`.
* :ref:`contains`.