Some theory

As you know there are two types of methods in PHP classes: static and non-static. To be called a non-static method needs an instance of its class, and static method can be called without instantiating of the class. 

In the meantime there are two very common questions:

• When to use non-static methods and when to use static methods?
• Is there any performance difference between static and non-static methods?

These are very common dilemmas among PHP developers. Most of developers guess that static methods must work faster because there is no object instance with all its properties involved to the call. Sounds logical. Is that actually true?

As I already mentioned above, and as you already know, the main difference between static and non-static metods is that static methods do not need an instance of the class to be called in the code. It means that for static methods there is no need to create object and keep in the memory. So, at least we can save some memory which can also affect the performance? Hmmm... we'll see...

So, it's time to do some very simple experiments for further analysis.

Apparently, the person who wrote this code has never heard about regular expressions. :)

<?php
$find = str_replace(",", "", $find);
$find = str_replace(".", "", $find);
$find = str_replace("/", "", $find);
$find = str_replace(" ", "", $find);
$find = str_replace("-", "", $find);
$find = str_replace("+", "", $find);
$find = str_replace("#", "", $find);
?>

Please, never repeat this! :)

There is a major security whole affecting several versions of Internet Explorer has been discovered recently. 

Microsoft has announced that Internet Explorer versions from IE6 to IE11 are all vulnerable to a glitch that could be used by hackers to get remote access to a victim’s PC.

"On completion of this investigation, Microsoft will take the appropriate action to protect our customers, which may include providing a solution through our monthly security update release process, or an out-of-cycle security update, depending on customer needs." , - Microsoft stated in their official press release.

According to W3Schools web browser usage stats this security issue may affect on 1 from 10 Internet users.

Believe you or not but such fails have been seen! :)

Hopefully, these days you won't see such a message anywhere. LOL

If you develop a PHP web application which may be used on a web server with older PHP version, you can run into a situation when some of the PHP functions in your application won't work at all, or won't work as expected.

In fact, you can handle those situations if you want to. However, it can make you application code not as nice as you want and a little heavier.