How to Learn PHP

PHP stands for PHP: Hypertext Preprocessor, and it’s a general-purpose scripting language used in web development. PHP is an open-source language that is able to embed into HTML. Using PHP simplifies HTML inputs and is less command heavy than C or Perl programming languages. Users may jump in and out of PHP mode as needed with the end goal to allow developers to write dynamically generated pages. The majority of the syntax within PHP is borrowed from C, Java and Perl; however, some unique PHP-specific elements exist within the language.

Modernday PHP is actually the successor to PHP/FI, created by Rasmus Lerdorf in 1994.

Originally, Lerdorf created PHP in C in order to track visits to his online resume. At that time, PHP stood for personal home page tools. Through several iterations, Lerdorf expanded on the tools in his version of PHP to include things like database interaction and dynamic web applications. He released his code in 1995, but it wasn’t until 1996 that the second generation of PHP took the shape of a programming language. PHP 2.0, as it was dubbed, had much more functionality than its original version, but it was still limited by the fact that only Lerdorf was working on it despite its small following of several thousand users.

PHP differs from client-side JavaScript in how the code is executed. With PHP, the code runs on the server and then in the HTML that is able to be sent to a client. Therefore, the client would see the results of running the code without actually seeing the code itself.

How Is PHP Used?

PHP is mainly used for server-side scripting. You may also use it for general CGI (common gateway interface) tasks such as collecting form data, creating dynamic page content or sending and receiving cookies. PHP is also used for command line scripting, which may be used for simple text processing.

Though it’s not very common today, PHP has historically been used to write desktop applications with a graphical interface via PHP-GTK. That project has been dormant for many years and isn't a realistic option for new desktop development, but it's worth knowing it exists if you encounter it in older PHP codebases.

All major operating systems support PHP including Linux, Microsoft Windows, macOS and many Unix variants. PHP works as a CGI processor or a module. It gives users the flexibility of choosing either procedural programming, object oriented programming or a mix of both. Beyond output HTML, PHP capabilities include outputting images, PDFs, any text including XHTML or any XML file. It works by auto-generating these files and saving them instead of printing it out and forming a server-side cache.

Another strong feature of PHP is that it supports a wide range of databases. It also has built-in support for working with JSON, XML, and other common data formats used to exchange information between systems. Most modern PHP projects rely on Composer, PHP's package manager, to install and manage third-party libraries, and follow PSR standards (PHP Standards Recommendations) to keep code consistent and interoperable across projects. It also supports all Java objects and uses them transparently as PHP objects. PHP has many useful text processing features, including ones that have Perl compatibility.

Today, thousands of companies use PHP in their tech stacks, such as Facebook, Slack, and Lyft. Many developers turn to PHP because it is open source, free to use, easy to learn, flexible and scalable. Modern PHP has evolved significantly since its early versions — PHP 8, for example, introduced a JIT compiler and stricter typing, and the current stable release is PHP 8.5. Most PHP developers today also work within a framework, most commonly Laravel, which adds routing, database tools, and other structure on top of the core language.

Frequently Asked Questions

PHP is a popular coding language used primarily for server-side scripting. It’s used in conjunction with other coding languages and most closely resembles Java, C and Perl. It may be helpful to learn other languages before picking up PHP. For more information, read the article about picking the right programming language to learn. This section will answer some common frequently asked questions about PHP.