join two collection in laravel code example

Example 1: laravel join

Inner Join 	: ->join('contacts', 'users.id', '=', 'contacts.user_id')
Left Join 	: ->leftJoin('posts', 'users.id', '=', 'posts.user_id')
Right Join 	: ->rightJoin('posts', 'users.id', '=', 'posts.user_id')
Cross Join 	: ->crossJoin('colors')

Advance Queries : 
----------------- 
 		->join('contacts', function ($join) {
            $join->on('users.id', '=', 'contacts.user_id')
                 ->where('contacts.user_id', '>', 5);
        })

Example 2: merge collections laravel

$collection = collect(['product_id' => 1, 'price' => 100]);

$merged = $collection->merge(['price' => 200, 'discount' => false]);

$merged->all();

// ['product_id' => 1, 'price' => 200, 'discount' => false]