multidimensional array using $array[]

Question

When reading the php manual on array push i found that it suggest using $array[]=$push to enter new entries.

so my question is how would I go about using this with multidimensional arrays in the most efficient way ie speed.

Examlple 1:

 $client[] = (0);
 $client[] = (1);
 $client[] = (2);
 $client[] = (3);
 $array[$i++]=$client;
 unset($client);

Example 2:

$array[$i++]= array(0,1,2,3);

Example 3: Note: I dont currently know of a good way to set the array key on this one

$entry = array(0,1,2,3);
array_push($array,$entry);

The 4 values nested in the array will be updated very frequently. To do this I would assume using the following method would be my best choice regarding speed and efficiency.

 $array[0][0]= $array[1][0]+1;

Spelling it out: I have individual clients with unique identifiers. I need to keep track of 4 integers for each client. I'm looking to the fastest/uses the lowest resources method.

All in all ill take any suggestion but im curious if example 1 is any better in terms of speed and resources then example 2.

Thanks, JT

ACTUAL CODE To TEST:

<?php
$array = array();

$i=0;
$t1 = microtime(true);
while ($i<10000){
$array[$i++]= array(0,1,2,3);
}
$time1 = microtime(true) - $t1;
$mem1 = memory_get_peak_usage(true);

//print_r($array);
$array = array();
//echo '<br><br>';

$i=0;
$t2 = microtime(true);
while ($i<10000){
$client[] = (0);
$client[] = (1);
$client[] = (2);
$client[] = (3);
$array[$i++]=$client;
unset($client);
}
$time2 = microtime(true) - $t2;
$mem2 = memory_get_peak_usage(true);

//print_r($array);
$array = array();
//echo ' <br><br>';

$i=0;
$t3 = microtime(true);
while ($i++<10000){
$entry = array(0,1,2,3);
array_push($array,$entry);
}
$time3 = microtime(true) - $t3;
$mem3 = memory_get_peak_usage(true);

//print_r($array);
//echo '<br><br>';

print 'example 1 - ' . $time1 . ' - ' . $mem1 . '<br/>';
print 'example 2 - ' . $time2 . ' - ' . $mem2 . '<br/>';
print 'example 3 - ' . $time3 . ' - ' . $mem3 . '<br/>';
?>

RESULTS:

example 2 - 0.212869294 S

example 1 - 0.251849988 S

example 3 - 0.748561144 S

So the array push is a NO GO! This was the average of about 15 runs with each loop counting to 100*1000 :)

Example 1 does not use $array[1], so the result is different. Can you post complete code for both Examples to make it clear what exactly you want to compare? — Dmitri Zaitsev
– Dmitri Zaitsev, Commented Sep 2, 2013 at 15:04

Matt Indeedhat Holmes · Accepted Answer · 2013-09-02 15:51:57Z

1

here is a quick dirty test for this

<?php
$t1 = microtime(true);

$array = array();

for ($i = 0; $i < 100000; $i++) {
  $client[] = (0);
  $client[] = (1);
  $client[] = (2);
  $client[] = (3);
  $array[]=$client;
  unset($client);
}

$time1 = microtime(true) - $t1;
$mem1 = memory_get_peak_usage(true);

$array = array();
$t2 = microtime(true);

for ($i = 0; $i < 100000; $i++) {
  $array[] = array(0=>array(0,1,2,3));
}

$time2 = microtime(true) - $t2;
$mem2 = memory_get_peak_usage(true);

$array = array();
$t3 = microtime(true);

for ($i = 0; $i < 100000; $i++) {
  $array[] = [0=>array(0,1,2,3)];
}

$time3 = microtime(true) - $t3;
$mem3 = memory_get_peak_usage(true);

print 'example 1 - ' . $time1 . ' - ' . $mem1 . '<br/>';
print 'example 2 - ' . $time2 . ' - ' . $mem2 . '<br/>';
print 'example 3 - ' . $time3 . ' - ' . $mem3 . '<br/>';

for me i found that the first example was the least time efficient but the most memory efficient and that example 3 slightly out performed 2 in time but was equal in memory

edited Sep 2, 2013 at 15:51

answered Sep 2, 2013 at 15:12

Matt Indeedhat Holmes

7255 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

tyler Over a year ago

When i looked over my examples i noticed an error. The problem with the test you can was that one had an array growing in size while the others overwrote themselves. I updated the code at the bottom of my answer

Matt Indeedhat Holmes Over a year ago

you bring up a strong point, i am ashamed of myself. ive changed my cod too

tyler Over a year ago

Did you rerun the test?

Matt Indeedhat Holmes Over a year ago

i did, i found that the first example was the least time efficient but the most memory efficient and that example 3 slightly out performed 2 in time but was equal in memory

Matt Indeedhat Holmes Over a year ago

i already have, there is verry little difference just the addition of [] to $array to prevent the override and a couple of $array = array()'s to reset $array before each test

|

Collectives™ on Stack Overflow

multidimensional array using $array[]

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related