How to turn multidimensional array to indexed array of imploded value?

I am using laravel 5. I queried the list of dates from this sql statement:

//query tarikh tamat kursus                    
$datatarikhTamat = DB::table('itemregistrationdetail')
                  ->select('itemregistrationdetail.daytamat_kursus', 'itemregistrationdetail.monthtamat_kursus', 'itemregistrationdetail.yeartamat_kursus')
                  ->where('itemregistrationdetail.itemregistrationid', $id)
                  ->get();
$data = json_decode($datatarikhTamat, true); 

The decoded query will show this output:

      array:4 [▼
      0 => array:3 [▼
      "daytamat_kursus" => 28
      "monthtamat_kursus" => "July"
      "yeartamat_kursus" => 2011
    ]
     1 => array:3 [▼
     "daytamat_kursus" => 27
     "monthtamat_kursus" => "0"
     "yeartamat_kursus" => 2013
    ]
    2 => array:3 [▼
     "daytamat_kursus" => 14
     "monthtamat_kursus" => "0"
     "yeartamat_kursus" => 2013
    ]
    3 => array:3 [▼
     "daytamat_kursus" => 11
     "monthtamat_kursus" => "April"
     "yeartamat_kursus" => 2014
     ]
    ]

day, month and year of each date are from different columns of the table. I want to have those date to grouped together and displayed in a table. For example: The muldtidimensiarray of :

    array:12 [▼
   0 => "28 July 1022"
   1 => "27 0 2013"
   2 => "14 0 2013"
   3 => "11 April 2014"
    ]

can be grouped using implode to turn into a string "11 April 2014".

I had using this code to implode the array but it results differently.

//tarikh tamat kursus
    //**************** format the value of the date************************  
    $data = json_decode($datatarikhTamat, true); 

    $val_arr = array();

    foreach($data  as $val)
    {
        foreach($val as $key => $value)
        {
             $val_arr[] = $value;
        }
    }

    $dataTarikhTamat = implode("-", $val_arr);
    dd($val_arr);

This will produce this output:

 array:12 [▼
   0 => 28
   1 => "July"
   2 => 2011
   3 => 27
   4 => "0"
   5 => 2013
   6 => 14
   7 => "0"
   8 => 2013
   9 => 11
   10 => "April"
   11 => 2014
   ]

How can I modify the codes to get an indexed array of the dates?

via Chebli Mohamed