func_get_args

(PHP 4, PHP 5, PHP 7, PHP 8)

func_get_argsLiefert Funktionsargumente als Array

Beschreibung

func_get_args(): array

Gibt die der aufrufenden Funktion übergebenen Argumente als Array zurück.

Die Funktion kann zusammen mit func_get_arg() und func_num_args() genutzt werden, um Funktionen mit einer variablen Anzahl von Argumenten zu implementieren.

Parameter-Liste

Diese Funktion besitzt keine Parameter.

Rückgabewerte

Gibt ein Array mit Kopien aller Argumente zurück, mit denen die benutzerdefinierte Funktion aufgerufen wurde.

Fehler/Exceptions

Die Funktion generiert eine Warnung, wenn sie außerhalb einer benutzerdefinierten Funktion aufgerufen wird.

Beispiele

Beispiel #1 func_get_args()-Beispiel

<?php
function foo()
{
    
$numargs func_num_args();
    echo 
"Anzahl der Argumente: $numargs \n";
    if (
$numargs >= 2) {
        echo 
"Das zweite Argument ist: " func_get_arg(1) . "\n";
    }
    
$arg_list func_get_args();
    for (
$i 0$i $numargs$i++) {
        echo 
"Argument $i ist: " $arg_list[$i] . "\n";
    }
}

foo(123);
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

Anzahl der Argumente: 3
Das zweite Argument ist: 2
Argument 0 ist: 1
Argument 1 ist: 2
Argument 2 ist: 3

Beispiel #2 func_get_args()-Beispiel mit Referenz- und Wert-Argumenten

<?php
function byVal($arg) {
    echo 
'Wie übergeben : 'var_export(func_get_args()), PHP_EOL;
    
$arg 'baz';
    echo 
'Nach Änderung : 'var_export(func_get_args()), PHP_EOL;
}

function 
byRef(&$arg) {
    echo 
'Wie übergeben : 'var_export(func_get_args()), PHP_EOL;
    
$arg 'baz';
    echo 
'Nach Änderung : 'var_export(func_get_args()), PHP_EOL;
}

$arg 'bar';
byVal($arg);
byRef($arg);
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:


Wie übergeben : array (
0 => 'bar',
)
Nach Änderung : array (
0 => 'baz',
)
Wie übergeben : array (
0 => 'bar',
)
Nach Änderung : array (
0 => 'baz',
)

Anmerkungen

Hinweis:

Seit PHP 8.0.0 sollte die func_*()-Familie von Funktionen in Bezug auf benannte Parameter weitgehend transparent sein, indem die Parameter so behandelt werden, als wären sie alle an der richtigen Stelle übergeben worden und fehlende Parameter durch ihre Standardwerte ersetzt. Diese Funktion ignoriert die Erfassung unbekannter benannter variadischer Parameter. Auf unbekannte benannte Parameter, die erfasst werden, kann nur über den variadischen Parameter zugegriffen werden.

Hinweis:

Wenn die Parameter als Referenzen übergeben werden, so finden sich alle Änderungen an diesen Parametern in den Rückgabewerten dieser Funktion wieder.

Hinweis: Diese Funktion gibt nur eine Kopie der übergebenen Argumente zurück und berücksichtigt keine (nicht übergebenen) Standardargumente.

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User Contributed Notes 10 notes

up
50
T.M.
17 years ago
Simple function to calculate average value using dynamic arguments:
<?php
function average(){
    return
array_sum(func_get_args())/func_num_args();
}
print
average(10, 15, 20, 25); // 17.5
?>
up
5
cobrattila at gmail dot com
2 years ago
If you want to get the arguments by reference, instead of func_get_args() you can simply use

<?php
function args_byref(&...$args) {
   
// Modify the $args array here
}
?>

Credits should go to Markus Malkusch for pointing this out on Stackoverflow.
https://stackoverflow.com/a/29181826/1426064
up
16
anderson at francotecnologia dot com
14 years ago
How to create a polymorphic/"overloaded" function

<?php
function select()
{
   
$t = '';
   
$args = func_get_args();
    foreach (
$args as &$a) {
       
$t .= gettype($a) . '|';
       
$a = mysql_real_escape_string($a);
    }
    if (
$t != '') {
       
$t = substr($t, 0, - 1);
    }
   
$sql = '';
    switch (
$t) {
        case
'integer':
           
// search by ID
           
$sql = "id = {$args[0]}";
            break;
        case
'string':
           
// search by name
           
$sql = "name LIKE '%{$args[0]}%'";
            break;
        case
'string|integer':
           
// search by name AND status
           
$sql = "name LIKE '%{$args[0]}%' AND status = {$args[1]}";
            break;
        case
'string|integer|integer':
           
// search by name with limit
           
$sql = "name LIKE '%{$args[0]}%' LIMIT {$args[1]},{$args[2]}";
            break;
        default:
           
// :P
           
$sql = '1 = 2';
    }
    return
mysql_query('SELECT * FROM table WHERE ' . $sql);
}
$res = select(29); // by ID
$res = select('Anderson'); // by name
$res = select('Anderson', 1); // by name and status
$res = select('Anderson', 0, 5); // by name with limit
?>
up
4
foxkeys at gmail dot com
6 years ago
Merge func_get_args() with function defaults
<?php
class utils {
 
/**
   * @param mixed[] $args
   * @param ReflectionMethod $reflectionMethod
   *
   * @return array
   */
 
public static function mergeArgsWithDefaults( $args, \ReflectionMethod $reflectionMethod ) {
    foreach (
array_slice( $reflectionMethod->getParameters(), count( $args ) ) as $param ) {
     
/**
       * @var ReflectionParameter $param
       */
     
$args[] = $param->getDefaultValue();
    }
    return
$args;
  }
}

class 
sampleParent {
  const
USER_FILE_TYPE_FILE = 'FILE';
  public function
select( $idUserFile = null, $idUserFileType = self::USER_FILE_TYPE_FILE ) {
    echo
'[$idUserFile=>' . $idUserFile . ', $idUserFileType=>' . $idUserFileType, ']<br/>' . PHP_EOL;
  }
}

class
sample extends sampleParent {
  const
USER_FILE_TYPE_IMG = 'IMG';
  public function
select( $idUserFile = null, $idUserFileType = self::USER_FILE_TYPE_IMG ) {
    return
call_user_func_array( 'parent::select', \utils::mergeArgsWithDefaults( func_get_args(), new ReflectionMethod( __CLASS__, __FUNCTION__ ) ) );
  }
}

$sample1 = new sampleParent();
$sample1->select();//Prints "" / self::USER_FILE_TYPE_FILE
$sample1->select(1);//Prints 1 / self::USER_FILE_TYPE_FILE
$sample1->select(2, 'test 1');//Prints 2 / "test 1"
echo '<br/>' . PHP_EOL;
$sample2 = new sample();
$sample2->select();//Prints "" / self::USER_FILE_TYPE_IMG
$sample2->select(3);//Prints 3 / self::USER_FILE_TYPE_IMG
$sample2->select(4, 'test 2');//Prints 4 / "test 2"
?>
up
3
mitko at edabg dot com
13 years ago
<?php
/*
This example demonstrate how to use unknown variable arguments by reference.
func_get_args() don't return arguments by reference, but
debug_backtrace() "args" is by reference.
In PHP 5 this have no particular sense, because calling with arguments by reference
is depreciated and produce warning.
*/

class foo {

    var
$bar = "default bar";
   
    function
foo(/*variable arguments*/) {
// func_get_args returns copy of arguments
//        $args = func_get_args();
// debug_backtrace returns arguments by reference           
       
$stack = debug_backtrace();
       
$args = array();
        if (isset(
$stack[0]["args"]))
            for(
$i=0; $i < count($stack[0]["args"]); $i++)
               
$args[$i] = & $stack[0]["args"][$i];
       
call_user_func_array(array(&$this, 'bar'), $args);
    }
   

    function
bar($bar = NULL) {
        if (isset(
$bar))
           
$this->bar = & $bar;
    }
}

$global_bar = "bar global";
$foo = & new foo();
echo
"foo->bar:    ".$foo->bar."</br>\n";
$foo->bar = "new bar";
echo
"global_bar:  ".$global_bar."</br>\n";
/*
Result:
foo->bar:    default bar</br>
global_bar:  bar global</br>
*/

$foo = & new foo(&$global_bar);
echo
"foo->bar:    ".$foo->bar."</br>\n";
$foo->bar = "new bar";
echo
"global_bar:  ".$global_bar."</br>\n";
/*
Result:
foo->bar:    bar global</br>
global_bar:  new bar</br>
*/

?>
up
1
Anonymous
21 years ago
You can pass a variable number of arguments to a function whilst keeping references intact by using an array. The disadvantage of course, is that the called function needs to be aware that it's arguments are in an array.

<?php
// Prints "hello mutated world"
function mutator($args=null) {
$n=count($args);
while(
$i<$n) $args[$i++] = "mutated";
}
$a = "hello";
$b = "strange";
$c = "world";
mutator(array($a, &$b, $c));
echo
"$a $b $c";
?>
up
3
OpenTechnologist
10 years ago
please note that optional parameters are not seen/passed by func_get_args(), as well as func_get_arg().

ex:

<?php
function testfunc($optional = 'this argument is optional..') {
   
$args = func_get_args();
   
var_dump($args);
    echo
$optional;
}
?>

test case #1:
testfunc('argument no longer optional..');

result for #1:
array(1) {
    [0]=>  string(20) "argument no longer optional.."
}
argument no longer optional..

test case #2:
testfunc('argument no longer optional..','this is an extra argument');

result for #2:
array(2) {
    [0]=>  string(29) "argument no longer optional.."
    [1]=>  string(25) "this is an extra argument"
}
argument no longer optional..

test case #3: -- RESULTS IN AN EMPTY ARRAY
testfunc();

result for #3:
array(0) {
}
this argument is optional..
up
0
ario [a] mail [dot] utexas [dot] edu
15 years ago
"Because this function depends on the current scope to determine parameter details, it cannot be used as a function parameter. If you must pass this value, assign the results to a variable, and pass the variable."

This means that the following code generates an error:

<?php

function foo($list)
{
  echo
implode(', ', $list);
}

function
foo2()
{
 
foo(func_get_args());
}

foo2(1, 2, 3);

?>

However, you can easily get around this by doing the following:

<?php

function foo($list)
{
  echo
implode(', ', $list);
}

function
foo2()
{
 
foo($args = func_get_args());
}

foo2(1, 2, 3);

?>

This captures the context from foo2(), making this legal.  You get the expected output:

"1, 2, 3"
up
0
daveNO at ovumSPAMdesign dot com
21 years ago
<?php
// How to simulate named parameters in PHP.
// By Dave Benjamin <dave@ovumdesign.com>

// Turns the array returned by func_get_args() into an array of name/value
// pairs that can be processed by extract().
function varargs($args) {
   
$count = count($args);
    for (
$i = 0; $i < $count; $i += 2) {
       
$result[$args[$i]] = $args[$i + 1];
    }
   
    return
$result;
}

// Example
function test(&$ref1, &$ref2) {
   
// Default arguments go here.
   
$foo = "oof";
   
   
// Do some magic.
   
extract(varargs(func_get_args()));

    echo
nl2br("\n\$var1 = $var1");
    echo
nl2br("\n\$var2 = $var2");
    echo
nl2br("\n\$foo = $foo\n\n");
   
   
// Modify some variables that were passed by reference.
    // Note that func_get_args() doesn't pass references, so they
    // need to be explicitly declared in the function definition.
   
$ref1 = 42;
   
$ref2 = 84;
}

$a = 5;
$b = 6;

echo
nl2br("Before calling test(): \$a = $a\n");
echo
nl2br("Before calling test(): \$b = $b\n");

// Try removing the 'foo, "bar"' from the following line.
test($a, $b, var1, "abc", var2, "def", foo, "bar");

echo
nl2br("After calling test(): \$a = $a\n");
echo
nl2br("After calling test(): \$b = $b\n");
?>
up
-1
maarten at ba dot be
10 years ago
it seems that this function only returns a copy and loses it's byref information, use this dirty non-efficient workaround instead:

at the moment of writing it currently returns all of them as references, instead of only the ones who are passed that way...

<?php
function func_get_args_byref() {
       
$trace = debug_backtrace();
        return
$trace[1]['args'];
}
?>
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