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    call_user_func_array

    (PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

    call_user_func_array — Call a callback with an array of parameters

    Description

    call_user_func_array(callable $callback, array $args): mixed

    Calls the callback given by the first parameter with the parameters in args.

    Parameters

    callback

    The callable to be called.

    args

    The parameters to be passed to the callback, as an array.

    If the keys of args are all numeric, the keys are ignored and each element will be passed to callback as a positional argument, in order.

    If any keys of args are strings, those elements will be passed to callback as named arguments, with the name given by the key.

    It is a fatal error to have a numeric key in args appear after a string key, or to have a string key that does not match the name of any parameter of callback.

    Return Values

    Returns the return value of the callback, or false on error.

    Changelog

    Version Description
    8.0.0 args keys will now be interpreted as parameter names, instead of being silently ignored.

    Examples

    Example #1 call_user_func_array() example

    <?php
    function foobar($arg, $arg2) {
    echo     __FUNCTION__, " got $arg and $arg2\n";
    }
    class     foo {
    function     bar($arg, $arg2) {
    echo     __METHOD__, " got $arg and $arg2\n";
    }
    }


    // Call the foobar() function with 2 arguments
    call_user_func_array("foobar", array("one", "two"));

    // Call the $foo->bar() method with 2 arguments
    $foo = new foo;
    call_user_func_array(array($foo, "bar"), array("three", "four"));
    ?>

    The above example will output something similar to:

    foobar got one and two
foo::bar got three and four

    Example #2 call_user_func_array() using namespace name

    <?php

    namespace Foobar;

    class     Foo {
    static public function     test($name) {
    print     "Hello {$name}!\n";
    }
    }

    call_user_func_array(__NAMESPACE__ .'\Foo::test', array('Hannes'));

    call_user_func_array(array(__NAMESPACE__ .'\Foo', 'test'), array('Philip'));

    ?>

    The above example will output something similar to:

    Hello Hannes!
Hello Philip!

    Example #3 Using lambda function

    <?php

    $func     = function($arg1, $arg2) {
    return     $arg1 * $arg2;
    };

    var_dump(call_user_func_array($func, array(2, 4)));

    ?>

    The above example will output:

    int(8)

    Example #4 Passing values by reference

    <?php

    function mega(&$a){
    $a = 55;
    echo     "function mega \$a=$a\n";
    }
    $bar = 77;
    call_user_func_array('mega',array(&$bar));
    echo     "global \$bar=$bar\n";

    ?>

    The above example will output:

    function mega $a=55
global $bar=55

    Example #5 call_user_func_array() using named arguments

    <?php
    function foobar($first, $second) {
    echo     __FUNCTION__, " got $first and $second\n";
    }

    // Call the foobar() function with named arguments in non-positional order
    call_user_func_array("foobar", array("second" => "two", "first" => "one"));

    // Call the foobar() function with one named argument
    call_user_func_array("foobar", array("foo", "second" => "bar"));

    // Fatal error: Cannot use positional argument after named argument
    call_user_func_array("foobar", array("first" => "one", "bar"));

    ?>

    The above example will output something similar to:

    foobar got one and two
foobar got foo and bar

Fatal error: Uncaught Error: Cannot use positional argument after named argument

    Notes

    Note:

    Callbacks registered with functions such as call_user_func() and call_user_func_array() will not be called if there is an uncaught exception thrown in a previous callback.

    See Also

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    User Contributed Notes 1 note

    up
    40
    sebastian dot rapetti at tim dot it
    3 years ago
    Using PHP 8, call_user_func_array call callback function using named arguments if an array with keys is passed to $args parameter, if the array used has only values, arguments are passed positionally.

    <?php

    function test(string $param1, string $param2): void
    {
    echo     $param1.' '.$param2;
    }

    $args = ['hello', 'world'];
    //hello world
    call_user_func_array('test', $args);

    $args = ['param2' => 'world', 'param1' => 'hello'];
    //hello world
    call_user_func_array('test', $args);

    $args = ['unknown_param' => 'hello', 'param2' => 'world'];
    //Fatal error: Uncaught Error: Unknown named parameter $unknown_param
    call_user_func_array('test', $args);
    ?>
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