PHP-数组唯一和计数元素

Question

I am developing a shopping cart and come across a problem with regards to unique purchases.

Let's say that there is a product "Product A" and the user buys this item 4 times, their shopping cart shows as "4" items in the basket, which is stored as:

$items = [
  "Product A" => array (),
  "Product A" => array(),
  "Product B" => array()
];

When they view the shopping cart, I want it to therefore show:

Product:          Quantity:

"Product A"          2
"Product B"          1

Therefore, the question is, whether or not it is possible to do a array_unique with a count? So, I could store all of the unique items but also get the number of items that they have ordered? Or is there an alternative approach to this problem?

Answer 1

You may want to change the structure of your array:

$items = [];

function addItem($name, array $data = []){
    global $items;
    $items[$name][] = $data;
}

function countItem($name){
    global $items;
    return count($items[$name]);
}

So $items will end up like this:

$items = [
    "Product A" => [
        array(),
        array(),
    ],
    "Product B" => [
        array()
    ]
];

$array[] = $element will create an empty array $array if it is undefined. Similarly, $array["a"][] = $element will create an empty array $array["a"] if it is not defined yet.

Or if you only want to store a count, you have to use if(!isset($array["a"])) $array["a"] = 0; before incrementing it with $array["a"]++ .

Answer 2

Following is the logic.

1) Create a blank array of product cart.

2) While adding item to array, check array_key_exists() .

3) If does not exist, add item to array as key and quantity as value (this is quantity).

4) If exists, increase quantity by one.

Thats it.