PHP Functions Call_user_func & Call_user_func_array

Call_user_func_array (callable $callback, array $param _arr)

Parameter 1: Call a callback function,

Parameter 2: The array parameter is the parameter of the callback function.

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

Parameter 1: called callback function

Parameter 2-n: The parameter of the callback function.

Compare the differences between the two. The second argument 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 differences between the two.

Look out please continue.

Scenario Two: Call a static function in the class.

Here's 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's 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 this: the first parameter of this function must be a valid callback function, non-static method Showage () is not allowed to be called.

The solution you need is:

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 calls of such dynamic functions, object instantiation must be done in advance,

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

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: Call_user_func_array and call_user_func Two functions are basically similar, but there are some differences when passing parameters on a call.

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

The second argument passed by the Call_user_func may be an array. If you have more than one parameter, you still need to list it in the form of a listing.