PHP language structure, its pros and cons

23.06.18 IT / PHP 7213

PHP today is used in the development of most sites and web applications. This language was conceived by the authors as a simple and affordable tool for creating dynamic pages, and I must say they did it. How did you create such a convenient tool for developing web projects?

If you look at the history of the language and the first versions, it becomes clear that the language embodied all the best features of existing programming languages ​​for desktop systems, for example, many functions resemble the behavior of functions from the language C or C ++ ... According to some sources, the development of PHP was influenced by languages ​​such as Perl, C, C ++, Java, Tcl.

How does PHP work ? It is known that site files are hosted on a server that is capable of processing scripts in a specific language, such as PHP. The server itself, for example, Apache, is written in a system programming language, for example, in C. That is, the server is a simple program on a specially prepared computer that is capable of receiving requests from the outside and sending responses to the client who requested the data. Since the server is essentially an ordinary program , it would be best to write the code for it in the same system language in which the server itself is written. But system languages ​​are complex, so the code needed to be simplified. For such purposes, the PHP language was conceived.

All the written code in PHP, at the moment the page starts loading, is loaded into the server's memory and the code is interpreted and parsed. If there are errors, the work stops and an error is issued, if not, the code is processed, translated into machine codes and executed.

PHP is a kind of add-on, analysis and parsing of PHP code happens at a lower level. Generally, when executing the code, simple PHP commands are translated into more complex low-level ones, for which various analyzers are used (lexical, syntactic, etc.), a translator is used that generates opcodes and commands - after that they are executed by a virtual machine and translated into a machine the code. In PHP, you can simply write echo "Hello World!" and this phrase will be displayed, but it is more difficult to display the same content on the screen in a lower-level language, it would be necessary to write a lot of preparatory code there before sending the data to output.

The main feature of PHP is the apparent simplicity and ease of development. On the one hand, this is a plus, you do not need to monitor the types of variables, you do not need to manage memory allocation and perform other routine operations. On the other hand, this ease has spawned many unprofessional scripts that can be insecure, difficult to maintain, etc. It's easy to get started with PHP development, but it takes experience to get things right. Code can be written using different programming paradigms, be it OOP or procedural style , or another paradigm. A well-written script has many factors. Maintaining certain rules for the visual design of the code is good practice - the code should have the same indentation, consistent naming of variables, functions, etc. In addition to the external design, the logic of the program itself is important - it is necessary to optimize the written code, check it for safety and other procedures.

Thus, PHP development can be of good quality, despite the ease of use of the language. But unlike low-level languages, PHP does not follow or teach the correct programming skills , so you should independently adhere to the established development rules according to the documentation. Documentation is available on the official PHP site, including Russian.