Laravel：此集合实例上不存在Property [name]

I am trying to transform json data for all products using Laravel's resource collections. But it is throwing error.

"Property [name] does not exist on this collection instance".

I checked official documentation, and they have implemented it in a similar way.

ProductController.php

public function index()
    {
        return new ProductCollection(Product::all());
    }

ProductCollection.php

namespace App\Http\Resources\Product;

use Illuminate\Http\Resources\Json\ResourceCollection;

class ProductCollection extends ResourceCollection
{
    /**
     * Transform the resource collection into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array
     */
    public function toArray($request)
    {
        return [
            'name' => $this->name,
            'price' => $this->price
        ];
    }
}

ProductResource.php

namespace App\Http\Resources\Product;

use Illuminate\Http\Resources\Json\JsonResource;

class ProductResource extends JsonResource
{
    /**
     * Transform the resource into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array
     */
    public function toArray($request)
    {
        return [
            'name' => $this->name,
            'description' => $this->detail,
            'price' => $this->price,
            'stock' => $this->stock,
            'discount' => $this->discount,
            'effectivePrice' => round($this->price * (1 - ($this->discount/100)), 2),
            'rating' => $this->reviews->count() > 0 ? round($this->reviews->sum('star') / $this->reviews->count(), 2) : 'No Ratigs Yet',
            'href' => [
                'reviews' => route('reviews.index', $this->id)
            ]
        ];
    }
}

NOTE: Working fine when not transforming the ProductCollection, i.e., when ProductCollection's toArray() function is like below:

public function toArray($request)
    {
        return parent::toArray($request);
    }

ProductCollection is for a collection of Products.
So you need to use foreach.

class ProductCollection extends ResourceCollection
{
    /**
     * Transform the resource collection into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array
     */
    public function toArray($request)
    {

        // final array to be return.
        $products = [];

        foreach($this->collection as $product) {

             array_push($products, [
                 'name' => $product->name,
                 'price' => $product->price
             ]);

        }

        return $products;
    }
}