Call to undefined function %s()¶
Description¶
This error is displayed when the called function is not defined. There are many places in the code where a function may be defined: in the PHP core engine, in PHP extensions, in dependencies, in the current file, in an included file. Also, since PHP 8.0, a function, disabled with the disable_functions
directive, is shown as undefined, rather than forbidden.
Example¶
<?php
undefined_function();
?>
Literal Examples¶
Call to undefined function undefined_function()
Call to undefined function shell_exec()
Call to undefined function mb_substr()
Solutions¶
The function has not been written in the code.
The function has not been included in the code before being called.
The function name has a typo.
The function is not defined in the current PHP version.
The function is not defined in any PHP extension version.
The function is not defined the current namespace, or the global namespace.
The
use
expression, used to import that function from another namespace, misses thefunction
keyword:use foo as A
instead ofuse function foo as A
.The function is actually a closure: a
$
is missing:$variable()
, instead ofvariable()
.This is actually a constant, and extra
()
were added.The function was disabled with
disable_functions
.
In previous PHP versions, this error message used to be %s() has been disabled for security reasons.