Call_user_func of PHP functions & Call_user_func_array

Call_user_func_array (callable $callback, array $param _arr)

Number 1: Call a callback function,

Parameter 2: Array parameters are the parameters of the callback function.

Call_user_func (callable $callback, $mixed $parameter, $mixed $ ...)

Parameter 1: callback function for Call

2-n: The number of parameters for the callback function.

The difference between the two is different oh. The second parameter of the former must be an array.

Case one: Call the normal function.

<?
Phpfunction Barber ($type) {    

Here, the first parameter directly specifies the name of the function.

<?
Phpfunction Barber ($type) {    

Or compare the difference between the two.

Look out please continue.

Scenario Two: Call a static function in the class.

Here are the Call_user_func_arr

Namespace Foo;class F {public static function ShowName ($name) {return strtoupper ($name);}} Echo Call_user_func_array (__namespace__. ' \f::showname ', Array (' vein ')); Echo Call_user_func_array (Array (__namespace__. ' \f ', ' showname '), Array (' vein '), $f = new F (), Echo Call_user_func_array (Array ($f, ' showname '), Array (' vein '));

Here are the Call_user_func

Namespace Foo;class F {public static function ShowName ($name) {return strtoupper ($name);}} Echo Call_user_func (__namespace__. ' \f::showname ', ' vein '); Echo call_user_func (Array (__namespace__. ' \f ', ' showname '), ' vein '); $f = new F (); Echo call_user_func (Array ($f, ' showname '), ' vein ');

Scenario Three: Dynamic method invocation

Call_user_func

Namespace Foo;class F {public Function showage ($age) {return $age + 100;}} Call_user_func (__namespace__. ' \f::showage ', 23);

Note here that if this is called, the system will error, prompting

Call_user_func () expects parameter 1 to am a valid callback, Non-static method Foo\f::showage () should not being called S
Tatically

Explain: The first parameter of this function must be a valid callback function, non-static method Showage () is not agreed to call.

The required solutions are:

Namespace Foo;class F {public static function ShowName ($name) {return strtoupper ($name);} Public Function Showage ($age) {return $age + 100;}} $f = new F (); echo call_user_func (Array ($f, ' showage '), 23);

For the invocation of this dynamic function, object instantiation must be done in advance,

The instantiated object is then passed into the function as the first argument.

Call_user_func_array:

Namespace Foo;class F {public static function ShowName ($name) {return strtoupper ($name);} Public Function Showage ($age) {return $age + 100;}} $f = new F (); echo Call_user_func_array (Array ($f, ' showage '), Array (23));

This is also possible.

To summarize: The two functions of Call_user_func_array and Call_user_func are basically similar, but there are some differences when passing parameters on a call.

Remember that the second parameter passed by the Call_user_func_array must be an array,

The second parameter passed by the Call_user_func may be an array. If you have multiple parameters, you need to list them.

Call_user_func & Call_user_func_array of PHP functions