.. _strict_types-declaration-must-have-0-or-1-as-its-value:

strict_types declaration must have 0 or 1 as its value
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		strict_types declaration must have 0 or 1 as its value: The ``strict_types`` pragma is a switch: ``0`` keeps the usual weak typing (with type coercion for scalar type declarations), and ``1`` turns on strict typing for the current file.
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	:og:title: strict_types declaration must have 0 or 1 as its value
	:og:description: The ``strict_types`` pragma is a switch: ``0`` keeps the usual weak typing (with type coercion for scalar type declarations), and ``1`` turns on strict typing for the current file
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Description
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The ``strict_types`` pragma is a switch: ``0`` keeps the usual weak typing (with type coercion for scalar type declarations), and ``1`` turns on strict typing for the current file. No other value makes sense, so PHP only accepts the literal integers ``0`` and ``1``; anything else, including ``true``, ``false``, or any other number, is rejected.

Example
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.. code-block:: php

   <?php
   
   declare(strict_types = 2);
   
   ?>


Literal Examples
****************
+ strict_types declaration must have 0 or 1 as its value

Solutions
_________

+ Use ``1`` to enable strict typing, or ``0`` to keep weak typing.

Related Error Messages
______________________

+ :ref:`declare(%s)-value-must-be-a-literal`
+ :ref:`strict_types-declaration-must-be-the-very-first-statement-in-the-script`
+ :ref:`strict_types-declaration-must-not`

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>`_.