Question

I have a small PHP script that is selecting a random sentence from an array

$prefixes = array('sentence 1', 'sentence 2');

echo $prefixes[rand(0,count($prefixes)-1)];

How can I make it not pick the same sentence twice in a row?

Edit: Sorry, yeah there will be around 100 sentences and they can be used over and over again just not twice in a row. It’s an on click event that re-loads the sentence to the page with AJAX and if it picks the same sentence twice in a row it looks like clicking the button hasn’t done anything as there is no page refresh. Thanks

Edit 2: Basically it’s a DIV with a sentence in, when you click a button it loads a new sentence into the DIV via AJAX and replaces the old sentence with the new one. Sometimes it was loading the same sentence twice in a row which gave the effect the button wasn’t doing anything

Answer 1

session_start();
$prev = isset($_SESSION['last_number']) ? $_SESSION['last_number'] : null;
do {
  $_SESSION['last_number'] = mt_rand(0,count($prefixes)-1);
} while ($_SESSION['last_number'] === $prev);
echo $prefixes[$_SESSION['last_number']];

Of course, make sure you have more than one element in $prefixes, or else it will get stuck in an infinite loop.