The code:

<?php
// Start sessions!
session_start();
// Is $_SESSION["count"] set? If yes, increase by one, if not set to one.
isset($_SESSION["count"]) ? $_SESSION["count"]++ :  $_SESSION["count"] = 1;
echo "This page has been loaded: {$_SESSION["count"]} time(s).";
?>
<br /> Reload the page. It's a simple counter using sessions to keep the count.

Each time you refresh the page the the count will increase with one. Remove the cookie to start from 1 again.

Look no further! This goes into your page, and it will make make the users’ browser refresh once your page is loaded under the picture that google displays.

<script type="text/javascript">
if (top.location != location) {
  top.location.href = document.location.href;
}
<script>

I might make some pictures for show and tell later.

<?php
a = 10;
$b = 44;
$a^=$b^=$a^=$b;
//$a = 44;
//$b = 10;
?>

If you’re having trouble reading that it might be a bit easier to write it all out.

<?php
$a = 10;
$b = 44;
$a = $a^$b;
$b = $b^$a;
$a = $a^$b;
//$a = 10;
//$b = 44;
?>

You might be thinking; “why not do just assign a temporary variable instead“, and that works great too. However you won’t feel warm and fuzzy inside. You won’t be able to show off with your one-line ninja code either. Assigning a temporary variable and XOR-Swap is about equal in performance – I’ve benchmarked this. A temporary variable will leave a footprint equal to the size of your variable, but memory is cheap, right? However using something like list($a, $b) = array($b, $a); is a lot slower – if you think about it that makes sense as you actually have to populate the array before assigning it to the variables in the list. When I say a lot slower, I mean a lot slower. I might post benchmarks for this in a later post.

One thing you have to worry about is if the the two variables you’re XOR-Swapping are not the same type or if they are of unequal length. XOR-Swapping $a = "hello"; $b = "world"; will work, but $a = "hello"; $b = "world!"; will break.

I don’t know if anyone will find what I write useful or even interesting, but if you do I would love to hear about it! Feel free to drop a me a personal message or write a comment. I’m looking for some work, so if you need somebody to do freelance for you hit me up!

Might find themselves waiting forever…