func_get_args

(PHP 4, PHP 5, PHP 7)

func_get_argsReturns an array comprising a function's argument list

설명

array func_get_args ( void )

Gets an array of the function's argument list.

This function may be used in conjunction with func_get_arg() and func_num_args() to allow user-defined functions to accept variable-length argument lists.

반환값

Returns an array in which each element is a copy of the corresponding member of the current user-defined function's argument list.

변경점

버전 설명
5.3.0 This function can now be used in parameter lists.
5.3.0 If this function is called from the outermost scope of a file which has been included by calling include or require from within a function in the calling file, it now generates a warning and returns FALSE.

오류/예외

Generates a warning if called from outside of a user-defined function.

예제

Example #1 func_get_args() example

<?php
function foo()
{
    
$numargs func_num_args();
    echo 
"Number of arguments: $numargs \n";
    if (
$numargs >= 2) {
        echo 
"Second argument is: " func_get_arg(1) . "\n";
    }
    
$arg_list func_get_args();
    for (
$i 0$i $numargs$i++) {
        echo 
"Argument $i is: " $arg_list[$i] . "\n";
    }
}

foo(123);
?>

위 예제의 출력:

Number of arguments: 3 
Second argument is: 2
Argument 0 is: 1
Argument 1 is: 2
Argument 2 is: 3

Example #2 func_get_args() example before and after PHP 5.3

test.php
<?php
function foo() {
    include 
'./fga.inc';
}

foo('First arg''Second arg');
?>

fga.inc
<?php

$args 
func_get_args();
var_export($args);

?>

Output previous to PHP 5.3:

array (
  0 => 'First arg',
  1 => 'Second arg',
)

Output in PHP 5.3 and later:

Warning: func_get_args():  Called from the global scope - no function
context in /home/torben/Desktop/code/ml/fga.inc on line 3
false

Example #3 func_get_args() example of byref and byval arguments

<?php
function byVal($arg) {
    echo 
'As passed     : 'var_export(func_get_args()), PHP_EOL;
    
$arg 'baz';
    echo 
'After change  : 'var_export(func_get_args()), PHP_EOL;
}

function 
byRef(&$arg) {
    echo 
'As passed     : 'var_export(func_get_args()), PHP_EOL;
    
$arg 'baz';
    echo 
'After change  : 'var_export(func_get_args()), PHP_EOL;
}

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

Output of the above example in PHP 7:


As passed : array (
0 => 'bar',
)
After change : array (
0 => 'baz',
)
As passed : array (
0 => 'bar',
)
After change : array (
0 => 'baz',
)

Output of the above example in PHP 5:


As passed : array (
0 => 'bar',
)
After change : array (
0 => 'bar',
)
As passed : array (
0 => 'bar',
)
After change : array (
0 => 'baz',
)

주의

Note:

이 함수는 인수를 현재 영역(scope)에 의존하기 때문에, 함수의 인수로 사용할 수 없습니다. 이 값을 함수에 넘겨야 한다면, 결과값을 변수에 할당하여 그 변수로 넘겨야 합니다.

Note:

인수가 참조로 전달되면, 인수에 대한 변화는 이 함수가 반환하는 값에 영향을 줍니다.

Note: This function returns a copy of the passed arguments only, and does not account for default (non-passed) arguments.

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User Contributed Notes 9 notes

up
46
T.M.
15 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
foxkeys at gmail dot com
3 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
16
anderson at francotecnologia dot com
11 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
3
mitko at edabg dot com
10 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
OpenTechnologist
7 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
12 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
18 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
0
Anonymous
18 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
maarten at ba dot be
7 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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