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array_key_first

(PHP 7 >= 7.3.0)

array_key_firstGets the first key of an array

Açıklama

array_key_first ( array $array ) : mixed

Get the first key of the given array without affecting the internal array pointer.

Değiştirgeler

array

An array.

Dönen Değerler

Returns the first key of array if the array is not empty; NULL otherwise.

Örnekler

Örnek 1 Basic array_key_first() Usage

<?php
$array 
= ['a' => 1'b' => 2'c' => 3];

$firstKey array_key_first($array);

var_dump($firstKey);
?>

Yukarıdaki örneğin çıktısı:

string(1) "a"

Notlar

İpucu

There are several ways to provide this functionality for versions prior to PHP 7.3.0. It is possible to use array_keys(), but that may be rather inefficient. It is also possible to use reset() and key(), but that may change the internal array pointer. An efficient solution, which does not change the internal array pointer, written as polyfill:

<?php
if (!function_exists('array_key_first')) {
    function 
array_key_first(array $arr) {
        foreach(
$arr as $key => $unused) {
            return 
$key;
        }
        return 
NULL;
    }
}
?>

Ayrıca Bakınız

  • array_key_last() - Gets the last key of an array
  • reset() - Bir dizinin dahili göstericisini ilk elemana konumlar
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User Contributed Notes 1 note

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1
webmaster at redinfo dot co dot kr
4 days ago
// if : php > 7
$arr = array('a'=>'apple','b'=>'bone','c'=>'company');
echo current(array_keys($arr));

// result: a
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