(PHP 4, PHP 5, PHP 7, PHP 8)
func_get_args — Returns an array comprising a function's argument list
DescriptionThis 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.
ParametersThis function has no parameters.
Return ValuesReturns an array in which each element is a copy of the corresponding member of the current user-defined function's argument list.
Errors/ExceptionsGenerates a warning if called from outside of a user-defined function.
ExamplesExample #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(1, 2, 3);
?>
The above example will output:
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 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);
?>
The above example will output:
As passed : array (
0 => 'bar',
)
After change : array (
0 => 'baz',
)
As passed : array (
0 => 'bar',
)
After change : array (
0 => 'baz',
)
Note:
As of PHP 8.0.0, the func_*() family of functions is intended to be mostly transparent with regard to named arguments, by treating the arguments as if they were all passed positionally, and missing arguments are replaced with their defaults. This function ignores the collection of unknown named variadic arguments. Unknown named arguments which are collected can only be accessed through the variadic parameter.
Note:
If the arguments are passed by reference, any changes to the arguments will be reflected in the values returned by this function. As of PHP 7 the current values will also be returned if the arguments are passed by value.
T.M. ¶Note: This function returns a copy of the passed arguments only, and does not account for default (non-passed) arguments.
20 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); ?>
16 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':
$sql = "id = {$args[0]}";
break;
case 'string':
$sql = "name LIKE '%{$args[0]}%'";
break;
case 'string|integer':
$sql = "name LIKE '%{$args[0]}%' AND status = {$args[1]}";
break;
case 'string|integer|integer':
$sql = "name LIKE '%{$args[0]}%' LIMIT {$args[1]},{$args[2]}";
break;
default:
$sql = '1 = 2';
}
return mysql_query('SELECT * FROM table WHERE ' . $sql);
}
$res = select(29); $res = select('Anderson'); $res = select('Anderson', 1); $res = select('Anderson', 0, 5); ?>
daveNO at ovumSPAMdesign dot com ¶
23 years ago
<?php
function varargs($args) {
$count = count($args);
for ($i = 0; $i < $count; $i += 2) {
$result[$args[$i]] = $args[$i + 1];
}
return
$result;
} function test(&$ref1, &$ref2) {
$foo = "oof"; extract(varargs(func_get_args()));
echo
nl2br("\n\$var1 = $var1");
echo nl2br("\n\$var2 = $var2");
echo nl2br("\n\$foo = $foo\n\n"); $ref1 = 42;
$ref2 = 84;
} $a = 5;
$b = 6;
echo
nl2br("Before calling test(): \$a = $a\n");
echo nl2br("Before calling test(): \$b = $b\n"); test($a, $b, var1, "abc", var2, "def", foo, "bar");
echo
nl2br("After calling test(): \$a = $a\n");
echo nl2br("After calling test(): \$b = $b\n");
?> foxkeys at gmail dot com ¶
9 years ago
Merge func_get_args() with function defaults
<?php
class utils {
public static function mergeArgsWithDefaults( $args, \ReflectionMethod $reflectionMethod ) {
foreach ( array_slice( $reflectionMethod->getParameters(), count( $args ) ) as $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();
$sample1->select();$sample1->select(1);$sample1->select(2, 'test 1');echo '<br/>' . PHP_EOL;
$sample2 = new sample();
$sample2->select();$sample2->select(3);$sample2->select(4, 'test 2');?> OpenTechnologist ¶
13 years ago
please note that optional parameters are not seen/passed by func_get_args(), as well as func_get_arg().
ex:
<?php
function testfunc($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.. hans at loltek dot net ¶
1 year ago
I wanted an associative list of arguments, in case some else does too, I'm leaving it here.
I hope PHP gets native support for this, because a core implementation would be faster than this userland backtrace+reflection implementation:
<?phpfunction func_get_args_associative(bool $populateMissingArgumentsWithDefaults = false): array
{
$trace = debug_backtrace(0, 2)[1];
$reflection = null;
if (isset($trace['class'])) {
$reflection = new \ReflectionMethod($trace['class'], $trace['function']);
} else {
$reflection = new \ReflectionFunction($trace['function']);
}
$ret = [];
foreach ($reflection->getParameters() as $param) {
if (array_key_exists($param->getPosition(), $trace['args'])) {
$ret[$param->name] = $trace['args'][$param->getPosition()];
} elseif ($populateMissingArgumentsWithDefaults) {
assert($param->isDefaultValueAvailable(), "i think all params are either in trace[args] or have default values");
$ret[$param->name] = $param->getDefaultValue();
}
}
return $ret;
}
?> art at geigel dot com ¶
2 years ago
The size of the array resulting from func_get_args(), for instance using count(), does not take into account parameters that have been assigned default values in the function definition.
Example:
function foo($bar=true) {
echo count(func_get_args());
}
foo();
// echoes 0
foo("bar");
// echoes 1
A useful condition to test for when a function needs to return default behavior (whatever that might be) when no value is present and the value of $bar could be true, false, null, etc.
info at ensostudio dot ru ¶
17 days ago
Note: this function returns current values of variables instead passed to function
<?php
function test(int $v) {
$v = 2;
var_export(func_get_args());
}test(1); ?>
maarten at ba dot be ¶
12 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'];
}
?>
mitko at edabg dot com ¶
16 years ago
<?php
class foo {
var
$bar = "default bar";
function
foo() {
$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";
$foo = & new foo(&$global_bar);
echo "foo->bar: ".$foo->bar."</br>\n";
$foo->bar = "new bar";
echo "global_bar: ".$global_bar."</br>\n";
?> ario [a] mail [dot] utexas [dot] edu ¶
18 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:
<?phpfunction foo($list)
{
echo implode(', ', $list);
}
function
foo2()
{
foo(func_get_args());
}foo2(1, 2, 3);?>
However, you can easily get around this by doing the following:
<?phpfunction foo($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"
Anonymous ¶
23 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
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";
?>
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