.. _syntax-error,-unexpected-identifier-"readonly",-expecting-"function"-or-"const":

syntax error, unexpected identifier "readonly", expecting "function" or "const"
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.. meta::
	:description:
		syntax error, unexpected identifier "readonly", expecting "function" or "const": This syntax error signals that ``readonly`` is still considered as an identifier, and not as a keyword.
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	:og:title: syntax error, unexpected identifier "readonly", expecting "function" or "const"
	:og:description: This syntax error signals that ``readonly`` is still considered as an identifier, and not as a keyword
	:og:url: https://php-errors.readthedocs.io/en/latest/messages/syntax-error%2C-unexpected-identifier-%22readonly%22%2C-expecting-%22function%22-or-%22const%22.html
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	:twitter:title: syntax error, unexpected identifier "readonly", expecting "function" or "const"
	:twitter:description: syntax error, unexpected identifier "readonly", expecting "function" or "const": This syntax error signals that ``readonly`` is still considered as an identifier, and not as a keyword
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Description
___________
 
This syntax error signals that ``readonly`` is still considered as an identifier, and not as a keyword. This happens when the underlying PHP version is too old for the source code.

Example
_______

.. code-block:: php

   <?php
   
   class X {
       readonly int $property;
   }
   
   ?>

Solutions
_________

+ Remove the ``readonly`` option.
+ Upgrade to PHP 8.1 or more recent.

Changed Behavior
________________

This error may appear following an evolution in behavior, in previous versions. See ` <https://php-changed-behaviors.readthedocs.io/en/latest/behavior/.html>`_.

Static Analysis
_______________

This error may be tracked down with the following static analysis rules: `Classes/ReadonlyUsage <https://exakat.readthedocs.io/en/latest/Reference/Rules/Classes/ReadonlyUsage.html>`_.