PHP添加数组的值

Question

I have an array that looks like this, this array represents number of products in a shopping cart

Array
(
    [0] => Array
        (
            [id] => 1
            [icon] => bus.png
            [name] => Web Development
            [cost] => 500
        )

    [1] => Array
        (
            [id] => 4
            [icon] => icon.png
            [name] => Icon design
            [cost] => 300
        )

    [2] => Array
        (
            [id] => 5
            [icon] => icon.png
            [name] => footer design
            [cost] => 300
        )

)

and i am trying to add the [cost] of each together, since it is a shopping cart I need to display the total. some people might buy single product or 2 or 3 so how do i display the total by adding the cost together I have tried using array_sum($products['cost']) and array_sum($products[0]['cost']) but that does not work

Answer 1

For PHP >= 5.5, you can take advantage of PHP's array_column() function

$total = array_sum(
    array_column(
        $myArray, 
        'cost'
    )
);

For earlier versions of PHP, you can emulate this using array_map():

$total = array_sum(
    array_map(
        function($value) { 
            return $value['cost']; 
        }, 
        $myArray
    )
);