What's faster in PHP, a big switch statement, or an array key lookup where the array initialisation is paid every time?

Question

What\'s faster in PHP, making a large switch statement, or setting up an array and looking up the key?

Now before you answer, I am well aware that for pure lookups t

Answer 1

I did some tests:

File array_gen.php

 $i,\n";

    echo ');
        echo $hash[$a];
    ';

File switch_gen.php:

Then:

php array_gen.php > array_.php
php switch_gen.php > switch.php

time tcsh -c 'repeat 1000 php array.php > /dev/null'
19.297u 4.791s 0:25.16 95.7%
time tcsh -c 'repeat 1000 php switch.php > /dev/null'
25.081u 5.543s 0:31.66 96.7%

Then I modified the loop to:

for($i = 'a'; $i < 'z'; $i++)
  for($j = 'a'; $j < 'z'; $j++)
    for($k = 'a'; $k < 'z'; $k++)

To create 17576, 3 letter combinations.

time tcsh -c 'repeat 1000 php array.php > /dev/null'
30.916u 5.831s 0:37.85 97.0%
time tcsh -c 'repeat 1000 php switch.php > /dev/null'
36.257u 6.624s 0:43.96 97.5%

The array method wins every time, even once you include setup time. But not by a lot. So I think I will ignore this optimization and go with whatever is easier.