array_walk(3) [php man page]
ARRAY_WALK(3) 1 ARRAY_WALK(3) array_walk - Apply a user supplied function to every member of an array SYNOPSIS
bool array_walk NULL (array &$array, callable $callback, [mixed $userdata]) DESCRIPTION
Applies the user-defined $callback function to each element of the $array array. array_walk(3) is not affected by the internal array pointer of $array. array_walk(3) will walk through the entire array regardless of pointer position. PARAMETERS
o $array - The input array. o $callback - Typically, $callback takes on two parameters. The $array parameter's value being the first, and the key/index second. Note If $callback needs to be working with the actual values of the array, specify the first parameter of $callback as a refer- ence. Then, any changes made to those elements will be made in the original array itself. Note Many internal functions (for example strtolower(3)) will throw a warning if more than the expected number of argument are passed in and are not usable directly as a $callback. Only the values of the $array may potentially be changed; its structure cannot be altered, i.e., the programmer cannot add, unset or reorder elements. If the callback does not respect this requirement, the behavior of this function is undefined, and unpre- dictable. o $userdata - If the optional $userdata parameter is supplied, it will be passed as the third parameter to the $callback. RETURN VALUES
Returns TRUE on success or FALSE on failure. ERRORS
/EXCEPTIONS If function $callback requires more parameters than given to it, an error of level E_WARNING will be generated each time array_walk(3) calls $callback. EXAMPLES
Example #1 array_walk(3) example <?php $fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); function test_alter(&$item1, $key, $prefix) { $item1 = "$prefix: $item1"; } function test_print($item2, $key) { echo "$key. $item2<br /> "; } echo "Before ...: "; array_walk($fruits, 'test_print'); array_walk($fruits, 'test_alter', 'fruit'); echo "... and after: "; array_walk($fruits, 'test_print'); ?> The above example will output: Before ...: d. lemon a. orange b. banana c. apple d. fruit: lemon a. fruit: orange b. fruit: banana c. fruit: apple SEE ALSO
array_walk_recursive(3), iterator_apply(3), list(3), each(3), call_user_func_array(3), array_map(3), information about the callback type, foreach. PHP Documentation Group ARRAY_WALK(3)
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CALL_USER_FUNC_ARRAY(3) 1 CALL_USER_FUNC_ARRAY(3) call_user_func_array - Call a callback with an array of parameters SYNOPSIS
mixed call_user_func_array (callable $callback, array $param_arr) DESCRIPTION
Calls the $callback given by the first parameter with the parameters in $param_arr. PARAMETERS
o $callback - The callable to be called. o $param_arr - The parameters to be passed to the callback, as an indexed array. RETURN VALUES
Returns the return value of the callback, or FALSE on error. CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 5.3.0 | | | | | | | The interpretation of object oriented keywords | | | like parent and self has changed. Previously, | | | calling them using the double colon syntax would | | | emit an E_STRICT warning because they were inter- | | | preted as static. | | | | +--------+---------------------------------------------------+ EXAMPLES
Example #1 call_user_func_array(3) example <?php function foobar($arg, $arg2) { echo __FUNCTION__, " got $arg and $arg2 "; } class foo { function bar($arg, $arg2) { echo __METHOD__, " got $arg and $arg2 "; } } // 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(3) using namespace name <?php namespace Foobar; class Foo { static public function test($name) { print "Hello {$name}! "; } } // As of PHP 5.3.0 call_user_func_array(__NAMESPACE__ .'Foo::test', array('Hannes')); // As of PHP 5.3.0 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))); /* As of PHP 5.3.0 */ ?> The above example will output: int(8) NOTES
Note Before PHP 5.4, referenced variables in $param_arr are passed to the function by reference, regardless of whether the function expects the respective parameter to be passed by reference. This form of call-time pass by reference does not emit a deprecation notice, but it is nonetheless deprecated, and has been removed in PHP 5.4. Furthermore, this does not apply to internal functions, for which the function signature is honored. Passing by value when the function expects a parameter by reference results in a warn- ing and having call_user_func(3) return FALSE (there is, however, an exception for passed values with reference count = 1, such as in literals, as these can be turned into references without ill effects -- but also without writes to that value having any effect --; do not rely in this behavior, though, as the reference count is an implementation detail and the soundness of this behavior is questionable). Note Callbacks registered with functions such as call_user_func(3) and call_user_func_array(3) will not be called if there is an uncaught exception thrown in a previous callback. SEE ALSO
call_user_func(3), information about the callback type, ReflectionFunction::invokeArgs, ReflectionMethod::invokeArgs. PHP Documentation Group CALL_USER_FUNC_ARRAY(3)