How to use array_walk on class method that does not fit the $callback parameter order

i have a two dimensional array e.g

(
    [0] => Array
        (
            [person_id] => 55487
            [score] => 1.30427
            [mistakes] => 103.874811
            [description] => first record
        )

    [1] => Array
        (
            [person_id] => 55487
            [score] => 1.30427
            [mistakes] => 103.874811
            [description] => second record
        )

)

then I have a class function called

public function saveData($dbConnection, $param) {
    // function definition here
}

now how to use the array_walk with this function ?

I tried

array_walk($myArray,[$this,'saveData'],$dbConnection,$param);

I tried

array_walk($myArray,[$this,'saveData'],[$dbConnection,$param]);

none of these work..how to do it ?

Answer

According to documentation of array_walk:

Especially this line:

If the optional userdata parameter is supplied, it will be passed as the third parameter to the callback.

The extra parameter $userdata has to be at the 3rd parameter of your $callback. There is no way to workround the parameter order in array_walk(). But your method is clear using $dbConnection as the 1st parameter in your saveData() method.

There are 2 sensible ways to solve this:

1. Change your class method. Either to store the database connection in your class instance to remove it entirely from the parameter needs:

   public function saveData($param) {
       $dbConnection = $this->$dbConnection; // has to set this attr. somewhere else.
       // function definition here
   }
   
   // ...
   
   // call it like this:
   array_walk($myArray, [$this,'saveData']);
   

   or change the parameter order accord to the $callback requirement

   public function saveData($param, $key, $dbConnection) {
       // function definition here
   }
   
   // ...
   
   // call it like this:
   array_walk($myArray, [$this,'saveData'], $dbConnection);
   
   

2. Keep the method. Use an intermediate callback function instead:

   // call it like this in your method:
   array_walk($myArray, function ($param, $key, $dbConnection) {
     return $this->saveData($dbConnection, $param);
   }, $dbConnection);