key

(PHP 4, PHP 5, PHP 7)

keyFetch a key from an array

Descrierea

key ( array $array ) : mixed

key() returns the index element of the current array position.

Parametri

array

The array.

Valorile întoarse

The key() function simply returns the key of the array element that's currently being pointed to by the internal pointer. It does not move the pointer in any way. If the internal pointer points beyond the end of the elements list or the array is empty, key() returns NULL.

Istoricul schimbărilor

Versiune Descriere
7.0.0 array is now always passed by value. Prior to this version, it was passed by reference if possible, and by value otherwise.

Exemple

Example #1 key() example

<?php
$array 
= array(
    
'fruit1' => 'apple',
    
'fruit2' => 'orange',
    
'fruit3' => 'grape',
    
'fruit4' => 'apple',
    
'fruit5' => 'apple');

// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name current($array)) {
    if (
$fruit_name == 'apple') {
        echo 
key($array).'<br />';
    }
    
next($array);
}
?>

Exemplul de mai sus va afișa:

fruit1<br />
fruit4<br />
fruit5<br />

A se vedea și

  • current() - Return the current element in an array
  • next() - Advance the internal pointer of an array
  • foreach

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