<?php
$obj_1 = new StdClass;
$obj_1->name = "Toby";
$obj_2 = new StdClass;
$obj_2->name ="Martha";
$obj_3 = new StdClass;
$obj_3->n = 5;
$ar1 = ['name'=> 'Paul'];
$ar2 = ['name'=> 'Jess'];
$ar3 = ['age'=> '19'];
$arr = [$obj_1, $obj_2];
$arr2 = [$ar1, $ar2, $ar3];

function my_array_column($arr, $name){
  $_ = [];

  foreach ($arr as $e){
    if (is_array($e)){
      $_[] = @$e[$name];
    }else if (is_object($e)){
      $_[] = @$e->$name;
    }
  }

  return $_;
};

function my_array_column2($arr, $name){
  return array_map(
    function ($e) use ($name) {
      if (is_array($e)){
        return @$e[$name];
      }else if (is_object($e)){
        return @$e->$name;
      }
    }
    ,$arr
  );
}


$res = implode("\n", my_array_column($arr, "name"));
echo $res;