略微加速

PHP官方手册 - 互联网笔记

PHP - Manual: func_get_args

2024-11-15

func_get_args

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

func_get_args — 返回一个包含函数参数列表的数组

说明

func_get_args(): array

获取函数参数列表的数组。

该函数可以配合 func_get_arg() 和 func_num_args() 一起使用，从而使得用户自定义函数可以接受自定义个数的参数列表。

返回值

返回一个数组，其中每个元素都是目前用户自定义函数的参数列表的相应元素的副本。

更新日志

版本 说明
5.3.0 该函数可以在参数列表中使用。
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. （不知道如何翻译跟好，直接参考例2即可明白）

错误／异常

在用户自定义函数外调用则会出现错误警告。

范例

示例 #1 func_get_args() 例子

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

foo(1, 2, 3);
?>

以上例程会输出：

Number of arguments: 3<br />
Second argument is: 2<br />
Argument 0 is: 1<br />
Argument 1 is: 2<br />
Argument 2 is: 3<br />

示例 #2 PHP 5.3 前后使用 func_get_args() 在的对比

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

foo('First arg', 'Second arg');
?>

fga.inc
<?php

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

?>

PHP 5.3 版本之前的输出： 

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

PHP 5.3 和之后的版本的输出: 

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

示例 #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);
?>

以上例程会输出：


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

注释

注意:

因为函数依赖于当前作用域以确定参数的细节，所以在 5.3.0 以前的版本中不能用作函数的参数。如必须传递此值时，可将结果赋与一个变量，然后用此变量进行传递。

注意:

如果参数以引用方式传递，函数对该参数的任何改变将在函数返回后保留。As of PHP 7 the current values will also be returned if the arguments are passed by value.

注意: 该函数仅仅是返回传递参数的一个副本，并且不包含没有传入的默认参数。

参见

add a noteadd a note

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
13 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
20 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
9 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'];
}
?>
add a noteadd a note

官方地址：https://www.php.net/manual/en/function.func-get-args.php

有任何技术问题请点击这里 网站运营推广招聘
IT PHP 编程语言 Linux 开发编程 科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库 面试 C/C++ Golang Git 算法 操作系统 正则表达式 Redis 互联网 MySql JavaScript 运维 软件 国际 架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业 硬件 电子 娱乐 设计 nginx 摄影 游戏 WordPress HTTP 团建 数码电器
冷却塔厂家 广告
-- --
php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 adodb手册 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 opcache预加载 Composer的Packagist资源 mysql面试题 PHP7添加redis扩展 [鸟哥]PHP FFI详解 - 一种全新的PHP扩展方式 Packagist / Composer 中国全量镜像 PHP获取指定函数定义在哪个文件中及行号 PHP mkdir()写出来的权限与mode值不符合 php设置cookie为httponly防止xss攻击 常用的php ADODB使用方法集锦
联系我们 半月雨文化 可降解耗材网 蓝云环保 78免费小説 上海网站seo优化 工程造价 币安app官网下载 seo查询
北京半月雨文化科技有限公司.版权所有 京ICP备12026184号-3