如何从键中获取数组元素的值

Question

以下是我的数组

Array(
[id] => 1
[user_id] => 30
[list] => Array
    (
        [0] => Array
            (
                [id] => 1
                [card_id] => 6
                [amount] => 400
            )

        [1] => Array
            (
                [id] => 2
                [card_id] => 3
                [amount] => 500
            )

    )
)

我想从上面的数组中获取 amount 键的值，它位于 list 键中。我想将该值存储在一个变量中。 P.S ：在 list 数组中它将有多个数组

编辑： 输出中应该有所有金额的总和。例如，上面的数组总和将是 900 是 $total_amount = 900

Answer 1

这是你想要的，简单的foreach：

$array = [
"id" => 1,
"user_id" => 30,
"list" => [
            [
                "id" => 1,
                "card_id" => 6,
                "amount" => 400,
            ],

        [

                "id" => 2,
                "card_id" => 3,
                "amount" => 500,
        ]

    ]
];

$totalAmount = 0;

foreach ($array["list"] as $array){
  $totalAmount += $array["amount"];
}

var_dump($totalAmount);

结果：900

Answer 2

一个衬垫 array_column and array_sum;

echo array_sum(array_column($array["list"], 'amount')); // 900

在线查看：https://3v4l.org/EsvJO

如何从键中获取数组元素的值

How to get values of array element from key

php

multidimensional-array

array-key