php stdclass storing data object instead click below...
$data["list"] =  array("0"=> (object) array("category_name"=>$catName)); 
                                            
                 
                
                
                                        
                            
                                
                                    	 Answer (1)
                                     
                                        
You can write something like that...
$data['list'] = (object) array(
"0" => (object) array(
"category_name"=>"category_name")
);