平成30/ 2018-10-22 00:45
PHP array_keys()

配列の要素だけを取得するので便利。


////////////////////////
$array = array(0 => 100, "color" => "red");
print_r(array_keys($array));
----
Array
(
    [0] => 0
    [1] => color
)



////////////////////////
$array = array("blue", "red", "green", "blue", "blue");
print_r(array_keys($array, "blue"));
----
Array
(
    [0] => 0
    [1] => 3
    [2] => 4
)


////////////////////////
$array = array("color" => array("blue", "red", "green"),
               "size"  => array("small", "medium", "large"));
print_r(array_keys($array));
----
Array
(
    [0] => color
    [1] => size
)



//////////////////////// Thanks.
array_keys
http://php.net/manual/ja/function.array-keys.php