The get_defined_functions Function

The get_defined_functions function returns a multidimensional array containing a list of all defined functions. The array contains two keys: 'internal' for built-in PHP functions and 'user' for user-defined functions. The function does not accept parameters.

Syntax

get_defined_functions();

Example

Get a list of all defined functions:

<?php
	function customFunction() {}
	$res = get_defined_functions();
	print_r(array_slice($res['internal'], 0, 3));
	print_r($res['user']);
?>

Code execution result (example):

[
	'zend_version',
	'func_num_args',
	'func_get_args'
]
['customFunction']

Example

Check for the existence of a specific function:

<?php
	$functions = get_defined_functions();
	if (in_array('strpos', $functions['internal'])) {
		echo 'Function strpos exists';
	}
?>

Code execution result:

'Function strpos exists'

Example

Count the number of user functions:

<?php
	function func1() {}
	function func2() {}
	$res = get_defined_functions();
	echo 'User functions count: ' . count($res['user']);
?>

Code execution result:

'User functions count: 2'

The get_defined_functions Function

Syntax

Example

Example

Example

See Also