key
key
(PHP 4, PHP 5, PHP 7)
key — Fetch a key from an array
Description
mixed key ( array &$array )
key() returns the index element of the current array position.
Parameters
-
array -
The array.
Return Values
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.
Examples
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);
}
?> The above example will output:
fruit1<br /> fruit4<br /> fruit5<br />
See Also
© 1997–2017 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://secure.php.net/manual/en/function.key.php
