How to create nested PHP value object? (class)

Question

I would like to create the following using class syntax:

$resp = new stdclass;

$resp->CategoryListResp->category[0]->categoryId = 1;
$resp->CategoryListResp->category[0]->categoryName = "Spel"; 
$resp->CategoryListResp->category[0]->iconUri = "PictoSpel.png";

$resp->CategoryListResp->category[1]->categoryId = 2;
$resp->CategoryListResp->category[1]->categoryName = "Transport";
$resp->CategoryListResp->category[1]->iconUri = "PictoTransport.png";

Should be easy but I cannot find the syntax for this. I will later output $resp in json format. I am aware I can also use arrays for this...

The json output shall be:

{"CategoryListResp":{"category":[{"categoryId":1,"categoryName":"Spel","iconUri":"PictoSpel.png"},{"categoryId":2,"categoryName":"Transport","iconUri":"PictoTransport.png"}]}}

Answer 1

You can also make your classes more explicit:

    class Category {
        public $categoryId = 0, $categoryName = '', $iconUri = '';
    }

    class Resp {
        public $categoryListResp = null;
        public function __construct() {
            $this->categoryListResp = new CategoryListResp();
        }
    }

    class CategoryListResp {
        public $category = array();
    }

    $resp = new Resp();
    $resp->categoryListResp->category[0]->categoryId = 1; 
    $resp->categoryListResp->category[0]->categoryName = "Spel";  
    $resp->categoryListResp->category[0]->iconUri = "PictoSpel.png"; 
    // etc.

ADDED (based on henq's comment). To fully utilize the class concept you would need to add some methods to the classes. Then you would not use -> for arrays, but call the respective methods. E.g.

class Category {
    public $categoryId = 0, $categoryName = '', $iconUri = '';
    public function __construct($id, $name, $icon) {
        $this->categoryId = $id;
        $this->categoryName = $name;
        $this->iconUri = $icon;
    }
}

class Resp {
    public $categoryListResp = null;
    public function __construct() {
        $this->categoryListResp = new CategoryListResp();
    }
    public function addCategory($index, $id, $name, $icon) {
        $this->categoryListResp->addCategory($index, $id, $name, $icon);
    }
}

class CategoryListResp {
    public $category = array();
    public function addCategory($index, $id, $name, $icon) {
        $this->category[$index] = new Category($id, $name, $icon);
    }
}

$resp = new Resp();        
$resp->addCategory(0, 1, "Spel", "PictoSpel.png");
$resp->addCategory(1, 2, "Transport", "PictoTransport.png");
// etc

You can modify this concept according to your needs.

Answer 2

You're almost there already:

$resp = new stdClass();
$resp->CategoryListResp = new stdClass();

$resp->CategoryListResp->category[0]->categoryId = 1;
$resp->CategoryListResp->category[0]->categoryName = "Spel"; 
$resp->CategoryListResp->category[0]->iconUri = "PictoSpel.png";

$resp->CategoryListResp->category[1]->categoryId = 2;
$resp->CategoryListResp->category[1]->categoryName = "Transport";
$resp->CategoryListResp->category[1]->iconUri = "PictoTransport.png";

print_r(json_encode($resp));

/* 
output:
{"CategoryListResp":{"category":[{"categoryId":1,"categoryName":"Spel","iconUri":"PictoSpel.png"},{"categoryId":2,"categoryName":"Transport","iconUri":"PictoTransport.png"}]}}
*/

Just send $resp to json_encode. Your code should work as is, however. It's better design to create class definitions for CategoryListResp and Category, rather than just using stdClass.