Why json_encode returns empty brackets?

Question

var_dump of $array returns this :

array (size=3)
  0 => 
    object(frontend\models\Notifications)[101]
      private '_attributes' (yii\db\BaseActiveRecord) => 
        array (size=5)
          'id' => int 1
          'created_on' => string '2015-11-12 12:12:15' (length=19)
          'user_id' => int 1
          'text' => string '2severity level is 2guardian is 5,Student_id 2 created a Level 2 discipline issue in school' (length=91)
          'is_seen' => int 0
      private '_oldAttributes' (yii\db\BaseActiveRecord) => 
        array (size=5)
          'id' => int 1
          'created_on' => string '2015-11-12 12:12:15' (length=19)
          'user_id' => int 1
          'text' => string '2severity level is 2guardian is 5,Student_id 2 created a Level 2 discipline issue in school' (length=91)
          'is_seen' => int 0
      private '_related' (yii\db\BaseActiveRecord) => 
        array (size=0)
          empty
      private '_errors' (yii\base\Model) => null
      private '_validators' (yii\base\Model) => null
      private '_scenario' (yii\base\Model) => string 'default' (length=7)
      private '_events' (yii\base\Component) => 
        array (size=0)
          empty
      private '_behaviors' (yii\base\Component) => 
        array (size=0)
          empty
  1 => 
    object(frontend\models\Notifications)[108]
      private '_attributes' (yii\db\BaseActiveRecord) => 
        array (size=5)
          'id' => int 2
          'created_on' => string '2015-11-12 12:12:15' (length=19)
          'user_id' => int 1
          'text' => string '2severity level is 2guardian is 5,Student_id 2 created a Level 2 discipline issue in school' (length=91)
          'is_seen' => int 0
     ................................
     ................................
     ................................

But the json_encode($array) returns [{}, {}, {}]. What I attempted: Tried changing the character encoding of the whole database to utf8_general_ci.

The character encoding is utf8_general_ci for my table and so is for my 'text' column of the table. What could be the issue?

Answer 1

The array you show has all the properties as private. this mean that this value are not available outside their class's scope.

you can look at this SO for some suggestion

Using json_encode on objects in PHP (regardless of scope)