The other responses focus on the differences between the two functions. This is true, but if the source array does not contain null
or 0
or ""
, ... (empty values) values you can benchmark the speed of the two functions:
<?php
function makeRandomArray( $length ) {
$array = array();
for ($i = 0; $i < $length; $i++) {
$array[$i] = rand(1, $length);
}
return $array;
}
function benchmark( $count, $function ) {
$start = microtime(true);
for ($i = 0; $i < $count; $i++) {
$function();
}
return microtime(true) - $start;
}
$runs = 100000;
$smallLength = 10;
$small = makeRandomArray($smallLength);
var_dump(benchmark($runs, function() {
global $small, $smallLength;
array_key_exists(rand(0, $smallLength), $small);
}));
var_dump(benchmark($runs, function() {
global $small, $smallLength;
!empty($small[rand(0, $smallLength)]);
}));
Which gave me the following results:
For a small array:
array_key_exists
: float(0.18357992172241)empty
: float(0.072798013687134)isset
: float(0.070242881774902)
For a relative big array:
array_key_exists
: float(0.57489585876465)empty
: float(0.0068421363830566)isset
: float(0.0069410800933838)
So if it's possible it's faster to use empty
or isset
.
-----------
https://stackoverflow.com/questions/6884609/array-key-existskey-array-vs-emptyarraykey