How to search item of collection with key?

Question

I got the following collection:

$this->items = collect([$productId => [
                    'name' => $product->title,
                    'price' => $product->price,
                    'is_sale' => $product->is_sale,
                    'sale_price' => $product->sale_price,
                    'sale_percent' => $product->sale_percent,
                    'can_use_promocode' => $product->can_use_promocode,
                    'qty' => 1,
                ]);
]);

How to search an item with key? In documentation (https://laravel.com/docs/5.2/collections) I dont see any methods for it

UPD: For example, user added an item to cart ($this->items). I want to check existence of item in cart (need to do it with key). Analog for php function array_key_exists, but for collections.

Answer 1

use has()

if($this->items->has('key_name_to_check')){
    ///your task if exists
}