如何在购物车中的PHP中具有相同名称的会话数组变量？

Question

I am creating a shopping cart in PHP using session variables to store the users product selections prior to checking out. For the most part, it works. The problem is that if a user selects lets say a 'red' shirt in size 'small', it adds it to the session variable as

    'products' =>
    array(size=1)
        'code' =>
            array(size=5)
                'product_size' => string 'Small'
                'quantity' => string '1'
                'product_code' => string 'sku'
                'name' => string 'shirt red'
                'price' => string '25'      

BUT if the user selects the same item in a different size, it overwrites the previous session variable with same code.

How can I make it so the user can get the same item in different sizes without overwriting the previous session variable?

Answer 1

I would build it like this

 ['products' => [
    $sku => [  //the actual sku value, not literally sku
        'price' => '25', //if it's common ( total = price x total_qty ), if not put a total here
         //'total_price' => 70
        'total_qty' => 3,
        'name' => string 'shirt red' //if its common
        'items' => [
             0 => [
                 'size' => 'Small'
                 'quantity' => '1'              
                 //'price' => 20
             ], 1 => [ 
                 'size' => 'Medium'
                 'quantity' => '2'              
                 //'price' => '25' 
             ]   
        ] //end items
   ]//end sku
]

Basically nest an item with the stuff is different for each item. I put price in commented form if its not common to the sizes.

You could also key the items on size if that is the main difference like this

  .....
   'items' => [
        'Small' => [
             'quantity' => '1'              
             //'price' => 20
         ], 'Medium' => [ 
             'quantity' => '2'              
             //'price' => '25' 
         ]   
    ]

This is less "flexible" but easier to minimize duplicate items. The items array keys are easier to check then a further nested 'size' key.

This should give you the idea, the actual structure is up to you and your use case, build it in the way that allows you the easiest access to the items, but is still flexible enough to accommodate all your products.

Last example, if the size and quantity are the only things that are different you could even do away with the nested array.

.....
'items' => [
    'Small' => '1','Medium' => '2'  
 ]

Also your array has this obvious error in your question.

   product_color' => string 'Small'

Answer 2

Keep product id as key and inside that have the attributes such as name, sku and types.

[
'products' => [
    'pid123' => [
        [
            'name' => 'abc',
            'sku' => 'sku-abc',
            'types' => [
                [
                    'colour' => 'red',
                    'size' => '42',
                    'qty' => 1
                ],
                [
                    'colour' => 'red',
                    'size' => '40',
                    'qty' => 2
                ]
            ]
        ]
    ],
    'pid789' => [
        [
            'name' => 'xyz',
            'sku' => 'sku-xyz',
            'types' => [
                [
                    'colour' => 'red',
                    'size' => '42',
                    'qty' => 1
                ],
                [
                    'colour' => 'red',
                    'size' => '40',
                    'qty' => 2
                ]
            ]
        ]
    ] 
]];

Type list will contain various size, colour, and quantity information.