php - 查找具有特定键名前缀的数组元素

Question

我有一个包含很多元素的关联数组，我想获得一个包含具有特定前缀的键名的所有元素的列表。

例子:

$arr = array(
  'store:key' => 1,
  'user' => 'demo',
  'store:foo' => 'bar',
  'login' => true,
);

// this is where I need help with:
// the function should return only elements with a key that starts with "store:"
$res = list_values_by_key( $arr, 'store:' );

// Desired output:
$res = array(
  'store:key' => 1,
  'store:foo' => 'bar',
);

Answer 1

你可以简单地做:

$arr = array(
  'store:key' => 1,
  'user' => 'demo',
  'store:foo' => 'bar',
  'login' => true,
);

$arr2 = array();
foreach ($arr as $array => $value) {
    if (strpos($array, 'store:') === 0) {
        $arr2[$array] = $value;
    }
}
var_dump($arr2);

返回:

array (size=2)
'store:key' => int 1
'store:foo' => string 'bar' (length=3)