php - How to send array in $_SESSION variable -

i want send array through session. here code:

    $result = mysqli_query($conn, trim($query1));                 if(!$result)                 {                 die('invalid query: '.mysqli_error($conn));                 }                        while ($data = mysqli_fetch_row($result))                  {                     echo ("<tr><td>$data[0]</td><td>$data[1]</td><td>$data[2]</td><td>$data[3]</td><td>$data[4]</td><td>$data[5]</td><td>$data[6]</td><td>$data[7]</td><td>$data[8]</td></tr>");             $temp[] = $data[0];                              }    $_session['data'] = $temp; 

but have fails. , in php file, want display these values.

foreach ($_session['data'] $key) {     # code... } 

how can save variable $_session?

probably might .

function sessionstore($sessionkey,$value) {     $sessionvalue = null;     if (is_array($value)) {         $sessionvalue = json_encode($value);     }     else{         $sessionvalue = $value;     }      $_session[$sessionkey] = $sessionvalue; }  function sessionretrieveall($sessionkey){      $value = $_session[$sessionkey];      $result = json_decode($value,true);      if (json_last_error() === json_error_none) {         return $result;     }      return $value; }  function sessionretrieve($sessionkey,$arraykey = null){     $arr = $this->sessionretrieveall($sessionkey);      if(!is_array($arr)){         return $arr;     }     else if($arraykey != null){         return isset($arr[$arraykey]) ? $arr[$arraykey] : null;     }      return $arr;  } 

and can implement

    $this->sessionstore('test',['a' => 'b', 'c' => 'd']);     print_r($this->sessionretrieve('test')); //returns array     echo $this->sessionretrieve('test','a'); // returns 'b'      $this->sessionstore('test2','just string');     echo $this->sessionretrieve('test2'); // returns 'just string' 

cheers !!!