PHP. Backend language #1

PHP is one of the most popular web development languages, but not all programmers are familiar with it, and many intentionally avoid it. Let's look at the key features of the language, the history of its development and how PHP is used today.

In the early days of the web, dynamic content sites were created in C and Perl, not the easiest of programming languages. Shortly after its release in 1995, PHP became the first language that a novice web developer could use to get a site up and running quickly. The acronym PHP itself originally stood for ‘Personal Home Page’.

PHP started out as a template language. A developer would add a tag to a web page, describing ways to interact with the page that were missing from the HTML standard. When the PHP code grew to several dozen lines, the text was moved to a separate file. The simplicity of the concept gave PHP a wide distribution, and people with very different views of its end use began to develop it. As a result, the language became hostage to a number of inconsistent decisions, which caused many developers to shun PHP as an illogical language for web development.

Over time, a large audience saved PHP. Among the language lovers, there were principled developers who did the work to optimize the code and set up the development process. Today, the language is quite comfortable for web development, regularly issuing new releases. PHP has got new tools for debugging, writing texts, formatting for standards and static code analyzers, as well as migration to new versions of the language.

PHP is an interpreted language. This means that the code is executed by the computer immediately when accessing the script, without being translated into machine code.

Here is a very simple PHP code where we create a var variable with a string value and display that value to the users of the site.

 
 
<?php
$var = "Hello, World!"; //Creating a variable does not require specifying the type
echo $var; //Output using a single operator

You can try running this code in PHP Sandbox and see what happens. We will talk more about the syntax of the language in a future article. For now let's look at the main pros and cons.

PHP pros:

• open source, free license;
• common language, large community;
• detailed documentation;
• many ready-made solutions for typical tasks;
• easy to get started - if desired, a beginner can implement any idea characteristic of the Web;

PHP cons:

• non-obvious conversion of data types leads to unpleasant surprises. In recent versions, this problem can be avoided by enabling strict typing;
• there is no multithreading in the usual sense; application paralleling is provided not so much by the language itself as by the natural parallelism of web queries;
• the contradictory choice of naming in the standard library of the language, due to its long development. Because of this, you have to check the language documentation regularly;
• narrow specialization: knowledge is mainly applicable to the web.

PHP comes with thousands of built-in functions. However, if you know what you want to achieve, the search will not take much time. There are ready-made implementations of common data structures, interfaces, classes and functions for building application frameworks. An important feature of PHP functions from the standard library is that they are available globally, they do not need to be imported and can be called anywhere in the program.

Third-party libraries are supported using a special Composer. - connected library control system. The necessary libraries are listed as a configuration list, and Composer already takes over the entire process of connecting the necessary libraries. This is a completely modern approach: for example, in Node.js the same tasks are solved using the npm manager, and in Python - using pip.

Today, PHP code is less likely to be embedded in page code than in the early days of the language. JavaScript has taken over the front-end niche, while PHP performs tasks behind the interface and is the most widely used server language. Examples of large PHP-based sites include YouTube, Wikipedia, and VK. For areas other than the backend, the language is rarely used - having to sacrifice versatility in favor of the technology's effectiveness in a particular area.

The three main things PHP allows you to do:

• Build web pages from modules. You can write separate blocks for the site header, menu, and footer with contacts, and assemble it all in the desired form at the specified addresses. You don't have to write the code for your own solution from scratch, because there are ready-made backend frameworks in the PHP world: Laravel for small and medium projects and Symfony for large ones, for example.
• Work with user data. Work with user data. PHP can communicate with both HTML and databases. This makes it an excellent intermediary between the user interface and the data world. For example, the PHP interpreter can add information from the HTML registration form to the database, and then verify information about the user at login.
• Write scripts for CMS. There are many content management systems on the market that use PHP as a development language and for plugins. Scripts for WordPress, Joomla and Drupal are written in PHP. . Even people unfamiliar with programming can create the necessary elements using PHP.

Modern PHP is an accessible and easy-to-learn language that allows you to quickly and inexpensively achieve your goals in a single, well-defined area. At the same time, it is a powerful language in which you can implement various architectural development patterns. Because of its specifics, it is unlikely to displace other popular languages, but it will continue to be used in its natural role, as well as many sites written in PHP, and it will continue to create new major web projects.

If you already use PHP, you might be interested to read about how different features of the language are supported in our main product, the ispmanager panel.We have described in detail the key points on working with PHP in the documentation. In particular, the ispmanager panel facilitates the installation of different versions of PHP on the same server and allows you to effectively administer Composer and PHP extensions.