PHP - 计算数组中项目的百分比

Question

我有以下数组

Array
(
[0] => Array
    (
        [rate] => normal-rate
        [quantity] => 1
    )

[1] => Array
    (
        [rate] => extra-rate
        [quantity] => 2
    )

[2] => Array
    (
        [rate] => extra-rate
        [quantity] => 1
    )

)

我正在尝试计算数组中额外费率项目的百分比，我可以直接执行此操作，还是应该首先通过计算数量并将所有内容添加到一起来创建新数组？

Answer 1

在一个班轮中它是：

$pers = count(array_filter($array, function($v) { return $v['rate'] == 'extra-rate'; })) / count($array);

简单的说法就是：

$count = 0;
foreach ($array as $v) {
    if ($v['rate'] == 'extra-rate') {
        $count++;
    }
}
$pers = $count / count($array);

考虑数量：

$ex_qty = 0;
$total_qty = 0;
foreach ($array as $v) {
    if ($v['rate'] == 'extra-rate') {
        $ex_qty += $v['quantity'];
    }
    $total_qty += $v['quantity'];
}
$pers = $ex_qty / $total_qty;