PHP: faster array populatin using mysql_fetch_array

In C++ and JavaScript it was recomm开发者_JAVA技巧ended to create an array with specified length, and then populate it. Is there a syntax to do so in PHP? Or there's no need because PHP's array is a hash?

ps: I'm populating an array from mysql using mysql_fetch_array and I'm running a loop to it so =(

You can use SplFixedArray from the Standard PHP Library (SPL), if performance is really important. In general reguluar php arrays will be fine, without worrying about the size of array required.

http://www.php.net/manual/en/class.splfixedarray.php

They work like arrays do in other langauges. From the docs "The advantage is that it allows a faster array implementation."

You can do something like that:

$size = 10;
$data = new SplFixedArray($size);
$i = 0;
while ($row = mysql_fetch_assoc($result)) {
    if($data->offsetExists($i)) {
        $data[$i] = $row;
    } else {
        $size += 10;
        $data->setSize($size);
        $data[$i] = $row;
    }
    $i++;
}

But my advice is stick to normal arrays.

You don't have to worry at all.
Despite of theoretical recommendations from some ancient book, in the real life practical usage the difference would be negligible and you'll never notice the difference.

Usual web-page seldom being populated with more than 100 rows from the database. Trust me, an array of such size is not a thing to worry about.
If it happen to have an array of much bigger size, you have to consider not to use arrays at all first.