PHP

I came across this sorting algorithm the other day called 'bogo sort'. This is a sort of joke sorting algorithm that is highly ineffective at actually sorting arrays. The name comes from the word 'bogus'.

Here is how it works.

1. Take an array.
2. Shuffle it.
3. If the array sorted then stop.
4. If the array is not sorted then return to step 2.

As you can see, this isn't so much a sorting algorithm, more of a game of chance. Due to the random nature of the sort you might need to wait a very long time before the array is actually sorted.

Here is an implementation of a bogo sort in PHP.

I have been doing some reading and watching lectures of programming theory recently and I was reminded of this algorithm I learned about in university. Binary searching an array is a divide and conquer algorithm that takes an array and searches for a value in that array by splitting the array into halves. The algorithm works like this.

Sorting colours is the sort of thing that you never really think about until you need to do it. Sorting a bunch of items by their colour is useful in a number of applications, but the simplest is just to display items to the user in a more controlled manner. As it happens sorting with colours is a much more complex topic than I originally thought and required digging into quite a bit more maths than I expected.

Incidentally, there is a whole world of colour maths that I didn't know existed until I started looking into this. It was worth learning about though.

Setting Up

To start with, I created a little Colour class so that I could have a standard way of storing a colour. This just takes the red, green and blue values for a colour and allows a simple way of accessing those values.

At the LAMP and Beyond III event (run by PHPNW) this weekend we set ourselves the task of giving PHP7 a go. Below is some nodes from that session.

This assumes that you’ve already installed PHP5.6 along with Apache and MySQL. Installing PHP5.6 via apt-get is fine as we just need some of the dependencies to be present.

To get the the code for PHP7 you need to clone from the PHP repo on Github.

git clone git@github.com:php/php-src.git php-src

Go into the php-src directory and run the ./buildconf command, this will generate a configuration file.

./buildconf

Before you run config you’ll need to install some dependencies (there are one or two).

New in PHP 5.5 is a group of functions that deal with password hashing and verification. This is such a common thing for PHP applications to do that it was decided to include it into the core of PHP. They effectively solve the problem of hashing and comparing passwords that just about every PHP developer has implemented at one point or another.

There are only a few functions available but they provide all of the functionality needed to create a hash value from a password, check if the hash is valid and to check if the password hash needs to be recreated.

To create a hash value from a password use the password_hash() function. The first parameter is the password string and the second value is the hashing algorithm to use. The value PASSWORD_DEFAULT here is a PHP constant that is currently set to the bcrypt algorithm and will be changed to better algorithms when and if they are found in newer versions of PHP.

The Monty Hall problem is a counter intuitive problem in probability mathematics that deals with picking the right prize from a set of three doors. The problem is named after the television celebrity Monty Hall and is loosely based on the USA game show Let's Make a Deal.

This has become a popular problem in programming as it is a good exercise in thinking through a problem to prove what outcome actually occurs. Lots of examples have been posted online so I thought I would sit down and attempt to solve it myself. The problem is most commonly summarised as follows (this example was taken from Rosetta Code):

I recently have started looking into making myself a PHP Zend Certified Engineer and after doing a bit of research I found that the standard PHP string and array functions appear to be a large part of the exam material. So as a starting point (and for future revision) I decided it might be a good idea to create a revision sheet for those functions.

XDebug is a great PHP debugging tool, but it also comes with a very useful profiler that can tell you all sorts of information about your PHP application. This includes things like memory footprint and CPU load but will also have detailed information about the entire callstack of the code that was run. To enable the profiler part of XDebug you just need to set up a few rules in your xdebug.ini file.

I have started to use virtual machines to develop sites rather than installing a local web server. This allows me to replicate the exact setup of the server I will be deploying to with ease. For each virtual machine I set up a shared folder which allows me to store the files locally whilst being able to run the code on the virtual machine. One thing I missed was the ability to use xdebug to debug the sites through Netbeans, so I set about trying to set up the virtual hosts to allow me to use xdebug remotely.

All that is needed was to add a xdebug.remote_connect_back clause to the xdebug.ini file found in the PHP configuration. Set this value to 1 to automatically connect back to any xdebug session that is created on the server.

I have talked before about running Selenium tests in PHPUnit but I have only recently come to properly automate things. Getting a Selenium server to start and stop in a script is relatively easy and can be done in a simple script. My original script for running a directory of PHPUnit tests was as follows. I will explain more about how this all works later on in this post.