php : PHP speed comparison : array_push() vs array[]

Published: 2 yearss ago

While reworking some of my older code to help make it more portable (and OO'd) I found myself questioning whether or not to use array_push or the array[] method to add item(s) to an existing array.

Keeping in mind that this was a one-dimensional array containing only integers I couldn't see any clear advantage for either method - so it came down to some benchmarking.

I wrote a short script to go through and add 100,000 integers to an array using each method and measure the time taken for each to execute (source below).

I then ran this test several times on a few different machines to acheive the following results: (note only 1 of these is a 'production' machine - hence the other two seem 'slow')

	array_push()	array[]
Server 1	0.3274998665	0.1879339218
	0.3268370628	0.1882231236
	0.3245189190	0.1875350475
Server 2	0.7468159199	0.4605989456
	0.6691300869	0.3637771606
	0.6654429436	0.3629529476
Server 3	0.1151399612	0.0791311264
	0.1176619530	0.0834369659
	0.1185541153	0.0826609135

As you can see - the array[] method is much quicker - on average 41% faster - than using array_push().

Conclusion: in a simple instance such as the one demonstrated above, the array[] method of adding items to an array in PHP is substantially faster than using array_push. While the operations themselves don't take much time at all (remember, the times above are for executing each operation 100,000 times) - the compounding effect of many of these such requests on a server with a lot of traffic/activity could make a substantial difference to overall load and speed.

PHP Source:

<?php

$items = 100000;

$array = array();
$start = microtime_float();

for ($i = 1; $i <= $items; $i++)
{
    array_push($array, $i);
}

$end = microtime_float();

echo "using <strong>array_push</strong> for " . number_format($items,0) . " items took " . number_format(($end-$start),10) . " seconds.<br />";

unset($array);
$array = array();

$start2 = microtime_float();

for($i = 1; $i <= $items; $i++)
{
	$array[] = $i;
}

$end2 = microtime_float();

echo "using <strong>array[]</strong> for " . number_format($items,0) . " items took " . number_format(($end2-$start2),10) . " seconds.";


function microtime_float()
{
    list($usec, $sec) = explode(" ", microtime());
    return ((float)$usec + (float)$sec);
}

?>

php : PHP speed comparison : array_push() vs array[]

PHP Source:

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