Undefined constant %s::%s

Description

The requested class constant could not be found.

The error message is distinct for the global constants, although there is no mention of class in this one.

Example

<?php

class X {
     const Z = 1;
     private A = 2;
}

echo X::Y;

?>

Literal Examples

  • Undefined constant X::CONSTANT

Solutions

  • Find the actual name of the requested class constant.

  • Find the actual class of the requested class constant.

  • Check the namespace, or its import.

  • Check the visibility of the class constant: it may be private, or protected.

  • Check the autoload system, to make sure the definition could be found.

  • Define the class constant in the class, or its traits, interfaces or parents.