Array Benchmarking

[RobertP]

results:

0.839771 << isset empty
2.519401 << array_key_exists empty
2.476911 << in_array empty

0.812198 << isset full
2.472904 << array_key_exists full
Fatal error: Maximum execution time of 30 seconds exceeded in /var/www/test.php on line 58

 

code:

<?php

$iterations = 1000000;
$data = array();
$dataFull = array();

for ($i = 0; $i <= 1024; $i++) {
    $dataFull[$i] = str_repeat('1', 1024);
}

$startTime = microtime(true);
for ($i = 0; $i <= $iterations; $i++) {
    $foo = isset($data[$i]);
}
$totalTime = microtime(true) - $startTime;
echo number_format($totalTime, 6) . ' << isset empty<br />';

//====

$startTime = microtime(true);
for ($i = 0; $i <= $iterations; $i++) {
    $foo = array_key_exists($i, $data);
}
$totalTime = microtime(true) - $startTime;
echo number_format($totalTime, 6) . ' << array_key_exists empty<br />';

//====

$startTime = microtime(true);
for ($i = 0; $i <= $iterations; $i++) {
    $foo = in_array($i, $data);
}
$totalTime = microtime(true) - $startTime;
echo number_format($totalTime, 6) . ' << in_array empty<br />';

echo '<br />';

$startTime = microtime(true);
for ($i = 0; $i <= $iterations; $i++) {
    $foo = isset($dataFull[$i]);
}
$totalTime = microtime(true) - $startTime;
echo number_format($totalTime, 6) . ' << isset full<br />';

//====

$startTime = microtime(true);
for ($i = 0; $i <= $iterations; $i++) {
    $foo = array_key_exists($i, $dataFull);
}
$totalTime = microtime(true) - $startTime;
echo number_format($totalTime, 6) . ' << array_key_exists full<br />';

//====

$startTime = microtime(true);
for ($i = 0; $i <= $iterations; $i++) {
    $foo = in_array($i, $dataFull);
}
$totalTime = microtime(true) - $startTime;
echo number_format($totalTime, 6) . ' << in_array full<br />';

?>

[kicken]

Did you have a point/question in this post?  Or just posting an FYI thing?

 

FYI,

1) isset is a language construct, array_key_exists is a function call.  Function calls have extra overhead, thus are slower

2) You're not using in_array properly.  in_array tests if a particular value exists in an array, not if a particular key exists

3) You should use isset(), except under one condition:  If you need to know if the key exists, but NULL is an acceptable value for that key (eg if it can contain say a DateTime object or null for none).

[trq]

Your point?

[RobertP]

this post was more of a FYI, but my reason for testing was to count how many unique visitors i had, so i would add each unique ip to the array (does not matter if in the key, or the value of the array entry).