PHP Manual: method

function method_exists(object|string $object_or_class, string $method): bool

Checks if the class method exists in the given object_or_class.

Returns true if the method given by method has been defined for the given object_or_class, false otherwise.

Version	Description
7.4.0	Class checks against inherited private methods now return `false`.

Example #1 method_exists() example

<?php
$directory = new Directory('.');
var_dump(method_exists($directory,'read'));
?>

The above example will output:

bool(true)

Example #2 Static method_exists() example

<?php
var_dump(method_exists('Directory','read'));
?>

The above example will output:

bool(true)

Note:
Using this function will use any registered autoloaders if the class is not already known.

Note:
The method_exists() function cannot detect methods that are magically accessible using the __call magic method.

method_exists