What is PHP? [Characteristics, Pros, and Cons]

Programming languages are something that computer programmers use to communicate with computer systems or other devices. What programmers do is write a program in any programming language, compile it, and then run it.

Additionally, there exist scripting languages that are also programming languages, but they do not require compilation. Instead, programs written in a scripting language are interpreted line by line at runtime. Programmers use a scripting language to write instructions for a runtime environment.

A plethora of scripting languages are available out there. Among them, PHP is an open-source and widely used scripting language for web development.

This blog post aims to make you familiar with PHP, its characteristics, advantages, disadvantages, and applications. But before proceeding, let us first discuss the definition of a scripting language and how a programming language and a scripting language differ from each other.

So, let us get started!

What is a Scripting Language?

A scripting language is a programming language, especially for a runtime environment that automates the execution of tasks. Basically, a scripting language is an interpreted language and not compiled. Therefore, programs written in a scripting language do not require compilation. Instead, the interpreter checks and runs programs line by line.

Moreover, the primary aim of any scripting language is to integrate and communicate with other programming languages. Besides PHP, some other popular scripting languages are Perl, Bash, Python, Ruby, and JavaScript.

Programming Language vs Scripting Language

The following table describes the major differences between a programming language and a scripting language:

What is PHP? [Definition]

PHP stands for Hypertext Preprocessor, which is an open-source, server-side scripting language. Though it is a general-purpose language, it is specially designed for developing dynamic websites and web applications. Originally, the acronym of PHP was Personal Home Pages.

As it is a server-side scripting language, we can do anything in the backend of the website using Hypertext Preprocessor. For example, it can retrieve data from forms, work with databases, send emails, send and receive cookies, generate dynamic page content, and create sessions.

Besides web development, this scripting language is ideal for developing a content management system (CMS). Some popular content management systems developed with Hypertext Preprocessor include WordPress, Drupal, Shopify, and WooCommerce.

History

A Danish-Canadian programmer, Rasmus Lerdorf, originally designed the Hypertext Preprocessor language in 1994. The development began when Lerdorf had written several common gateway interface (CGI) programs in C for his personal homepage. Later, he extended those CGI programs to work with databases and web forms and started referring them collectively to “Personal Home Page/Forms Interpreter" or PHP/FI.

However, with a Personal Home Page/Forms Interpreter, it was possible to create only simple static and dynamic websites. Later, Lerdorf released Personal Home Page Tools (PHP Tools) version 1.0, which had the basic functionality of today’s HyperText Preprocessor.

In 1997, a team of developers officially released Personal Home Page/Forms Interpreter 2. In the same year, two developers, namely Zeev Suraski and Andi Gutmans, rewrote the original parser of the language and released PHP 3. They changed the language’s name to the recursive acronym: Hypertext Preprocessor (PHP).

Suraski and Gutmans then moved on to rewrite Hypertext Preprocessor’s core and developed the Zend Engine in 1999. They released PHP 4 in 2000, which was powered by the Zend Engine.

Furthermore, the year 2004 witnessed the release of PHP 5, powered by the Zend Engine II. It included many new features, such as support for the object-oriented programming paradigm and various performance enhancements.

Followed by PHP 6 and 7, the year 2020 witnessed the release of PHP 8. It included features such as Just-In-Compilation (JIT), syntax changes and additions, type changes and addition, and many other additional changes.

Syntax

The Hypertext Preprocessor script begins with <?php and ends with ?>.

<?php
//code
?>

Any Hypertext Preprocessor file consists of PHP scripting code, along with client-side scripts, i.e., JavaScript and HTML tags. The default file extension for the Hypertext Preprocessor file is .php.

Furthermore, you also create a file that contains only Hypertext Preprocessor script and not HTML tags or JavaScript code. We refer to such files as pure PHP files.

Characteristics

The following are the remarkable characteristics of Hypertext Preprocessor:

1. Loosely-Typed

Hypertext Preprocessor is a loosely-typed scripting language. This means that it supports defining variables without declaring their data types. At the execution time, the data type of the variables is taken care of, depending upon the values you assign to them. More interestingly, you can even change the name of a variable dynamically.

2. Open-Source

It is an open-source source scripting language that anyone can use. Also, you can simply download PHP and start writing your own applications since all its components are free to use.

3. Interpreted and Case Sensitive

It is an interpreted language, i.e., the interpreter reads and executes code line by line, and there is no need for compilation. Moreover, this language is case-sensitive only at the time of declaring variables. Otherwise, all methods, user-defined functions, and classes are not case-sensitive.

4. Cross-Platform Compatibility

Hypertext Preprocessor is a cross-platform language that can run on any operating system, including Windows, Linux, macOS, UNIX, and environments. The most popular environments it supports are XAMPP (Windows, Apache Server, MySQL, Perl, and PHP) and LAMP (Linux, Apache, MySQL, PHP).

Moreover, it is platform-independent. Meaning that the Hypertext Preprocessor script developed on one operating system can run on other operating systems.

5. Error-Reporting and Exceptions

The Hypertext Preprocessor provides error reporting constants, such as E_ERROR, E_WARNING, E_PARSE, and E_STRICT to generate warnings or error alerts at runtime. Also, it supports the exception handling mechanism to throw errors and catch them anytime during the program execution.

6. Memory Usage Information

It provides functions, such as memory_get_usage() or memory_get_peak_usage(), that represents the memory usage information. These functions help developers optimize their code.

7. Object-Oriented

Hypertext Preprocessor follows the object-oriented programming concepts. As a result, it supports data encapsulation and inheritance, which increases the code execution speed.

8. Magic Constants

These are predefined constants in Hypertext Preprocessor that we can call during specific events. There are eight magic constants and all of them begin with the double underscore (__). They are as follows:

• (__DIR__)
• Class name (__CLASS__)
• Namespace (__NAMESPACE__)
• Function name (__FUNCTION__)
• Method name (__METHOD__)
• Line number (__LINE__)
• File path (__FILE__)

The aforementioned are some of the major characteristics of the Hypertext Preprocessor. Other well-known characteristics of this programming language include image manipulation using the GD library, session tracking, user sessions management, cookies and sessions support, shell command-line execution, Zip archives compression, and the list is endless.

Advantages and Disadvantages of PHP

Advantages

The following are the notable upsides of the Hypertext Preprocessor:

• It is a versatile scripting language that supports integration with various databases, programming languages, and web development technologies, such as MySQL , JavaScript, HTML, and CSS,
• Since it supports various databases, it enables effective storage and retrieval of data.
• It is one of the fastest scripting languages that let you observe the effects of changes made to the code immediately in the browser. To put it simply, it provides faster results than other scripting languages.
• Hypertext Preprocessor scripts do not depend on web browsers to run applications. Instead, they depend on web servers.
• It has a low learning curve. If you are familiar with the C language, you can easily learn the Hypertext Preprocessor.
• The powerful library support enables you to use various function modules for effective data representation.
• It has a simple structure and does not require developers to write lengthy and sophisticated code.
• It is a more stable scripting language than the other ones and provides consistent support.

Disadvantages

The following are the significant downsides of the Hypertext Preprocessor:

• As it is an open-source language, anyone can get access to its ASCII text files. Hence, it is not a secure language.
• It is not ideal for large and complex content-based web applications.
• It is not component modular, and hence, it becomes difficult to manage web applications developed using the Hypertext Preprocessor.
• You cannot change the core behavior of the online applications developed using this language.

Who Uses PHP?

Many tech giants use the Hypertext Preprocessor language to develop incredible web projects, CMS, and many other things. The following are some popular companies that leverage PHP:

1. Facebook: This tech giant uses the Hypertext Preprocessor language for creating desktop applications and creating and editing images.
2. Wikipedia: Wikipedia is among the most popular sources of information on the internet, and it is developed using the Hypertext Preprocessor language.
3. Content Management Systems (CMSs): Popular content management systems, such as WordPress, Joomla, Drupal, Magento, Shopify, etc., are built on PHP.
4. Web Hosting Platforms: Many popular web hosting providers , including Siteground, Bluehost, and Whogohost, leverage this scripting language to run their hosting servers.

Applications of PHP

Hypertext Preprocessor allow us to develop the following:

• Web applications and web pages
• eCommerce applications
• Web content management systems (CMSs)
• GUI-based applications
• Flash applications

Additionally, the scripting language is suitable for graphics designing, image processing, and data representation.

PHP Hello World Program

The following is a simple Hypertext Preprocessor program embedded in the HTML tags that outputs ‘Hello World!” in the web browser:

<!DOCTYPE html>
<html>
<body>
<h1>Welcome to TechGeekBuzz!</h1>

<?php
echo"Become a Tech Professional here";
?>

</body>
</html>

Output

Conclusion

PHP is a server-side, open-source scripting language that is primarily used for web development. Due to its features, such as platform independence, cross-platform compatibility, fast load time, object-oriented, etc., many tech giants like Facebook, Spotify, etc., leverage this language for creating web applications or server-side scripting.

We hope this article has helped you gain better insights into PHP, its features, advantages, disadvantages, and applications.

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