PHP Switching between two variables equally without using database

问题

i need to switch between two variables so i am able to serve two variables equally

for example i have

$ad1
$ad2

i want to serve both ads equally using a light method with no database

using random method won't serve both equally

can you please guide me how to achieve this ?

回答1:

But the random method (50/50) should serve both equally, given enough requests.

And it is the simplest solution imho.

<?php
$ad1 = '<img src... >';
$ad2 = '<img src...2 >';

echo mt_rand(0, 1) ? $ad1 : $ad2;
?>

回答2:

• You can use memcache (recommended)
• You can keep track of the last used variable in a file on the server (not recommended)
• You can use time() and use its mod by 2 as your decision maker (still not an exactly equality as you wanted)

(I think, on the long run, rand will serve you great)

来源：https://stackoverflow.com/questions/1993312/php-switching-between-two-variables-equally-without-using-database