The What
Description
The PHP construct call_user_func calls (invokes) a callback and passes the parameters (if any) to it. You are calling the callback by the full qualified name given to it in the first parameter. If the callback returns a value, then that value is returned by call_user_func.
Watch these videos first
Before you tackle call_user_func, make sure you first watch callable and callback. call_user_func works on both of these constructs.
Parameters
callback- The callable to be called (invoked).
parameter- Parameter(s) to be passed to the callback. Specify them by the needs of the callback, i.e. based on its parameter list.
Return Values
If the callback returns a value, then call_user_func returns that value; else it returns NULL. On error, it returns FALSE.
Show It in ActionBasic
Let’s see the call_user_func function in action. In this video, you will see how it works.
Break. Go rest your noodle for a couple of minutes.
Go DeepPro
In this video, you will go deeper into the instruction.
Calling MethodsPro
How do you call object and static methods with call_user_func? How do you call closures?
See It In Popular TechnologiesPro
Let’s look at call_user_func in Laravel, Symfony, and WordPress. You will see how prevalent it is used.
WhenPro
When do you use call_user_func versus one of the other ways to call a callback?
