在多维数组的第二个数组中按键Count()

Question

我有以下数组

$_POST[0][name]
$_POST[0][type]
$_POST[0][planet]
...
$_POST[1][name]
$_POST[1][type]
$_POST[1][planet]

现在我想计算所有的$_POST[x][type]。怎么做呢?

(如果我将反转多维数组，它将工作我猜像这样:)

$count = count($_POST['type']);

如何计算原始结构中的"类型"?

Answer 1

$type_count = 0;
foreach($arr as $v) {
    if(array_key_exists('type', $v)) $type_count++;
}

Answer 2

在您的例子中，这行得通:

$count = call_user_func_array('array_merge_recursive', $_POST);
echo count($count['name']); # 2

Answer 3

$count = 0;
foreach ($_POST as $value) {
   if (isset($value['type']) {
      $count++;
   }
}

Answer 4

PHP5.3 style

$count = array_reduce (
    $_POST,
    function ($sum, $current) {
        return $sum + ((int) array_key_exists('type', $current));
    },
    0
);

Answer 5

使用set操作:

$key = 'type';
$tmp = array_map($_POST, function($val) use ($key) {return isset($val[$key]);});
$count = array_reduce($tmp, function($a, $b) { return $a + $b; }, 0);

所以你可以把它缩减为array_filter:

$key = 'type';
$count = count(array_filter($_POST, function($val) use ($key) { return isset($val[$key]);}));