.. _structures-addzero:

.. _adding-zero:

Adding Zero
+++++++++++

  Adding 0 is useless, as 0 is the neutral element for addition. Besides, when one of the operands is an integer, PHP silently triggers a cast to integer for the other operand. 

This rule also report using ``+`` with variables, proeprties, etc. which triggers an automated conversion to integer.

It is recommended to make the cast explicit with ``(int)``.

.. code-block:: php
   
   <?php
   
   // Explicit cast
   $a = (int) foo();
   
   // Useless addition
   $a = foo() + 0;
   $a = 0 + foo();
   
   // Also works with minus
   $b = 0 - $c; // drop the 0, but keep the minus
   $b = $c - 0; // drop the 0 and the minus
   
   $a += 0;
   $a -= 0;
   
   $z = '12';
   print +$z + 1;
   
   ?>
Connex PHP features
-------------------

  + `addition <https://php-dictionary.readthedocs.io/en/latest/dictionary/addition.ini.html>`_
  + `short-assignation <https://php-dictionary.readthedocs.io/en/latest/dictionary/short-assignation.ini.html>`_


Suggestions
___________

* Remove the +/- 0, may be the whole assignation
* Use an explicit type casting operator (int)




Specs
_____

+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Short name   | Structures/AddZero                                                                                                                                                                      |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Rulesets     | :ref:`All <ruleset-All>`, :ref:`Analyze <ruleset-Analyze>`, :ref:`CE <ruleset-CE>`, :ref:`CI-checks <ruleset-CI-checks>`, :ref:`Rector <ruleset-Rector>`                                |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Exakat since | 0.8.4                                                                                                                                                                                   |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| PHP Version  | All                                                                                                                                                                                     |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Severity     | Minor                                                                                                                                                                                   |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Time To Fix  | Instant (5 mins)                                                                                                                                                                        |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Precision    | High                                                                                                                                                                                    |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ClearPHP     | `no-useless-math <https://github.com/dseguy/clearPHP/tree/master/rules/no-useless-math.md>`__                                                                                           |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Examples     | :ref:`case-thelia-structures-addzero`, :ref:`case-openemr-structures-addzero`                                                                                                           |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Available in | `Entreprise Edition <https://www.exakat.io/entreprise-edition>`_, `Community Edition <https://www.exakat.io/community-edition>`_, `Exakat Cloud <https://www.exakat.io/exakat-cloud/>`_ |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+