How do I use a class method as a callback function?

Question

If I use array_walk inside a class function to call another function of the same class

class user
{
   public function getUserFields($userIdsArr         


        

Answer 1

To call a class method as a callback function in another class method, you should do :

public function compareFucntion() {
}

public function useCompareFunction() {
  usort($arrayToSort, [$this, 'compareFucntion'])
}