History of PHP
The PHP language is over 20 years old. It was developed by Dane Rasmus Lerdorf in 1994 as a simple add-on that showed the number of visits to his personal page. Then he called it simply – Personal Home Page.
The language has evolved over the years. Three years ago, the seventh edition came out. It is much more efficient than previous versions of PHP – 5th and 6th:
- On average twice as fast as PHP 5.
- Uses 50% less memory when processing requests.
- It extends the existing declaration of parameters in methods.
- Reworked and removed obsolete code, which is about 180 thousand lines.
- There are many syntactic improvements.
- So, today PHP continues to be relevant and in demand among web developers.
It is often said that PHP is a language for beginners, it is not intended for creating large enterprise projects. This is not true. There are quite a few services written in PHP whose creators have become billionaires. For example, the social networks Facebook and VKontakte are written in PHP. Such popular CMS as WordPress, Drupal, “1C-Bitrix” are also written in PHP. And a large part of Google services is also written in this language.
The world’s largest companies use the PHP language.
PHP has a very low entry threshold. This is a language that will allow you to write small websites in just a month of learning. And in the future, developing your skills, you will be able to program already highly loaded industry solutions that the world’s leading companies need.
PHP is currently the most in-demand programming language. It holds a market share of 24.6%. Approximately the same is occupied by Java with its 21.1%. And the third language, C#, is already far behind, at 9.8%.
PHP, Java and C# are the most popular languages for employers. Demand for programming languages according to HH and My Circle.
The popularity rating of programming languages is based on the vacancies of the employer, and in the next 5 years this ratio is likely to remain unchanged.
PHP developer salary levels
According to HeadHunter statistics, the maximum salary for a PHP programmer is 2500$ . If we divide salaries by levels of professional development of a programmer, then the numbers are as follows:
- Junior Developer — from $700/month
He is just entering the profession, knows how to write something and has commercial programming experience of about 2-3 months.
- Middle Developer — from $1300/month
Can cope with 90% of tasks and has programming experience from 6 months to 1 year.
- Senior Developer — from $2000/month
He can solve any problem in PHP, design a solution, architecture, select code and train junior and middle programmers to perform these tasks.
Full range of web developer skills
Let’s look at what set of knowledge a beginner should master in order to engage directly in backend development:
HTML + CSS – page markup languages. You need to know and understand the basics, as you will have to work with ready-made markup.
PHP is the core of the site, a scripting language that works at the server level and interacts with the server structures on which the web project is built.
SQL is a structured query language used to manage databases, such as MySQL.
Linux – yes, Linux. Windows is not intended to be used as a server operating system, although PHP can run on both Windows and Linux. As part of the training, it is not necessary to use Linux specifically, but it is important to know that in real projects, servers usually run under this OS.
“PHP 7. In the original”, authors Dmitry Koterov, Igor Simdyanov.
“PHP Objects, Patterns, and Programming Techniques” by Matt Zandstra.
“Developing Web Applications with PHP and MySQL” by Luke Welling, Laura Thomson.
“Learning PHP 7. A Guide to Building Interactive Websites” by David Sklyar.
Create a simple script
Let’s take a simple PHP example and create a small script. We will not delve into the syntax of the language and the purpose of the operators in detail, but only visually show how PHP interacts with HTML.
First, we need to install the PHP compiler on the computer. Since we found out that PHP is a server-side language, there are special ready-made web server assemblies that include, in addition to PHP, other useful tools, such as the MySQL DBMS. One of these assemblies is Open Server. To write the code, we will use the Sublime Text 3 text editor.
Let’s go to the domains folder of the Open Server web server and create a new example folder in it. Let’s create 2 files inside the example folder: index.html and handler.php.
Few words about web standarts
Why should a web developer know standards
Standards are written and adopted by the W3C, a non-profit organization founded by Tim Berners-Lee. It consists of many working groups: they include representatives from browser companies, major universities, research institutes, and other organizations. Participants discuss with browser developers the design and implementation of the API, and then develop common standards.
This is how the W3C Standards Development Group description looks like
Here are the benefits of web standards and why you should learn them:
No need to write crutches. If you have come up with a new feature for your site, you do not need to write it separately for each browser and take into account all the features of the software interface. It’s much easier to use jQuery methods, which will behave the same in both Chrome and Firefox. But it is more correct to use the same methods in all browsers that work predictably.
It is not necessary to learn new specifications. Developers are not afraid that the browser will come out with a spec that will break the old functions of their web application. If you do not know about the existence of a feature, then you can simply not use it and live in peace.
You can find out how technology will develop. For example, in some standards it is written that after some time new color spaces will appear. So, we will be able to discuss in advance with the designer how to implement them.