After a little test, although the results are not conclusive, I would
say that isset(), and also that array_key_exists() may even use isset()
(or similiar) internally as a first step -let's remember that isset()
only does a "fast search" and it returns FALSE if the value is NULL; on
the other hand, array_key_exists() returns TRUE even if the value is
NULL- I said this (as an hypotesis) because the difference in time when
the key exists and when it doesn't is quite big, sometimes about 10
times slower.
The script I used to test it was this (it is assumed that any "extra"
operation affected both loops equally)
<?php
$arr_test = array( 'key' => array( 1 => -1 ) );
$num_oprs = 1000;
$start = micro_time();
for ( $i = 0; $i < $num_oprs; $i ++ ) {
if ( isset($arr_test['key'][1]) ) ;
}
echo '<p>isset: ', micro_time() - $start, "</p>\n";
$start = micro_time();
for ( $i = 0; $i < $num_oprs; $i ++ ) {
if ( array_key_exists(1, $arr_test['key']) ) ;
}
echo '<p>array_key_exists: ', micro_time() - $start, "</p>\n";
function micro_time( ) {
return preg_replace('/^0(\.\d+) (\d+)$/X',
'$2$1', microtime());
}
?>
Nikolay Rastegaev wrote:
Please, answer:
what construction works faster:
if ( isset ( $result [$i] ["key"] ) )
{ do something; }
or
if ( array_key_exists ( "key", $result [$i] ) )
{ do something; }
?
--
Atentamente,
J. Rafael Salazar Magaña
Innox - Innovación Inteligente
Tel: +52 (33) 3615 5348 ext. 205 / 01 800 2-SOFTWARE
rsalazar@xxxxxxxxxxxx
http://www.innox.com.mx
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