PHP Introduction - An Ultimate Guide to Basics

1. Introduction to PHP Programming

PHP introduction tutorial comprises detailed information about what is this programming language, and how this intro can impart greater awareness to absolute beginners, so that they may think of initiating a web development career. Further, this basic and introductory tutorial is also helpful for advanced programmers, and it covers advanced PHP topics as well as basics and is based on the latest version PHP 8.2.

1.1. Why PHP is a Popular Language?

• Basically, PHP is a server-side language that runs on the backend of a website or a server.
• Also, PHP can be used separately or within an HTML markup to obtain the results.
• The extensive usage of PHP in web applications and in the development of various CMS like WordPress, Joomla, Drupal, etc.
• Therefore, its vast usage and applications make it quite a popular scripting language among developers and have a wide developer community.

1.2. What is PHP Programming Language?

• First of all, PHP is a recursive backronym and stands for Hypertext PreProcessor.
• The most stable release of the PHP script is 8.2.1 in 2023.
• Secondly, PHP is one of the widely used programming languages and its popularity has spanned over the decades.
• Also, there is no cost to using PHP and it is free to utilize.
• Moreover, PHP code runs over popular databases like MySQL, Oracle, Microsoft SQL Server, etc.
• Furthermore, PHP generates output for the user in the form of HTML markup.
• Therefore, PHP is a handful tool for developing dynamic web pages.
• Importantly, PHP is a powerful scripting language that runs on the server-side.

1.3. What are PHP Filename Extensions?

Normally, when we save a PHP script in a file, it is given an extension to make it executable by the interpreter/compiler. There are many filename extensions of the PHP language that can be used for a file to make it executable by the interpreter. Plus, the most used PHP filename extension is .php. These PHP filename extensions are listed below:

1.4. What is PHP-GTK?

• PHP-GTK is a helpful PHP extension as it is useful in language binding implementation.
• Language binding is a term, which is referred to linking two existing languages.
• Here, PHP-GTK enables the developers to write PHP code in an object-oriented interface.
• In simple words, PHP-GTK is the enhancement of PHP that empower developers to write cross-platform applications with a Graphical User Interface.
• Also, PHP-GTK is available for both Windows and Linux users.

2. Is PHP a Scripting Language?

Sometimes, a scripting language is considered a very high-level language for a high level of abstraction. This section will cover information about scripting languages, usage of scripting languages, and some of the most popular scripting languages.

2.1. What is a Scripting Language?

• With each passing day, the world, which is already a global village, is emerging and evolving rapidly in almost every aspect of life due to technological advancements.
• Hence, there is a necessity for automation, to perform certain jobs and resultantly lessen the workload.
• Therefore, a scripting language plays its role in automating a runtime-system.
• Consequently, the workload is shifted to the machine and especially the IT industry thereafter.
• Importantly, a scripting language is interpreted rather than compiled to save time and boost performance.

2.2. What are the types of Scripting Languages?

Basically, there are two types of scripting languages:

a. Server-Side Scripting Language

• These types of scripting languages use the resources of a remote server.
• These scripts are compiled on a server and display the output in HTML form.
• These types of scripts are helpful for clients/browsers.
• Node.Js, PHP, Java, Python, Ruby, etc. are examples.

b. Client-Side Scripting Language

• These scripting languages run on the client side i.e. a browser.
• Client-side scripting language solely relies on a browser, and there is no server involved.
• Initially, the script is downloaded in the browser and then executed.
• Client-side scripts are added to improve web page functionality.
• Javascript, AJAX, Jquery, etc. are examples.

3. PHP Differences From OTHER Languages

3.1. What is the Difference Between PHP and HTML?

HTML is a web markup language and the acronym HTML stands for HyperText Markup Language. Whereas, PHP is a programming language that runs often on the server-side. The subsequent table summarizes the comparison between PHP and HTML.

3.2. What is the Difference Between PHP and ASP.NET?

The acronym ASP stands for Active Server Pages. Further, ASP is a .NET framework and is developed by Microsoft. Let's examine what is the difference between PHP and ASP.NET. The below table summarizes the comparison of PHP with ASP.NET.

4. PHP Basics For Beginners

4.1. How to Start Coding in PHP?

Due to the reputation of the PHP programming language, it has become the developer's prime choice over the past years. As a noob developer, there is a necessity to have some know-how of fundamental web languages before commencing with PHP. These include the following:

• HTML Language
• CSS Language
• JavaScript Language

However, only HTML is sufficient for starting programming with PHP.

4.2. Why do Developers Like to Code in PHP Language?

Considering PHP is so popular among developers, there is a reason for that. Beneath are some of the features of PHP that make it so much popular.

• Easy to use
• Efficient in execution
• More reliable security at server-side
• Too much flexibility
• Similarity with other languages

Popular PHP Applications

Following are some popular PHP applications that give it so much fame:

• Facebook: The largest social media website is coded in PHP makes it most compelling.
• WordPress: Approximately 30% of the websites on the internet are hosted by popular CMS WordPress, which is primarily a PHP framework.

4.3. What are the Benefits of Using PHP?

Due to the robust programming methodologies, PHP is not confined to producing HTML solely. Preferably, it can display images, videos, pdf files, etc. Following are certain PHP benefits that are adequate to take PHP as a programmer's primary choice:

• Nearly, all web servers, operating systems, and databases can run the PHP script.
• When executed on the server-side, it generates dynamic content.
• PHP gives many varieties of output like text, HTML, JSON, image, binary data, JSON, etc.
• It can perform several operations on the server like creating, opening, writing, reading, and deleting files.
• PHP has its reputation due to data collection using HTML forms.
• It can encrypt data to make it secure and safe.
• Also, Cookies can be sent and received using a PHP script.
• PHP can add, delete, and edit the database.
• Further, It supports both the Command-line interface (CLI) and the Graphical User Interface (GUI).
• Too many frameworks of PHP are available in the market to help developers in Rapid Application Development (RAD).

4.4. Write "Hello World" PHP Program

It is important to know that, there are two methods to integrate PHP and HTML. One way is to write PHP in HTML markup, whereas, the other way is to write HTML within the PHP script. Examine the subsequent "Hello World PHP Program" in two different ways to understand it more vividly.

<!Doctype HTML>
<html>
	<head>
		<title>PHP Introduction</title>
	</head>
	<body>
		<h4><?php echo "Hello, World!";?></h4>
	</body>
</html>

<!Doctype HTML>
<html>
	<head>
		<title>PHP Introduction</title>
	</head>
	<body>
		<?php echo "<h4>Hello, World!</h4>";?>
	</body>
</html>

4.5. Output of "Hello World" PHP Program

Both of the above examples will produce the same result on the screen. The server process the PHP code and returns only HTML markup to the browser. The output of this hello world PHP program is as follows:

4.6. An Advanced PHP Program

The following example is another PHP program. It will check the browser of the user and display it on the screen.

<?php

	echo $_SERVER['HTTP_USER_AGENT'];

?>

4.7. Output of Advanced PHP Program

The above line of PHP script will display the output on the screen similar to the following output.

4.8. What's Next?

Hopefully, this intro to PHP tutorial covered all the basics and knowledge for beginners as well as advanced web developers. Navigate to the next tutorials to enhance your PHP skills and gain in-depth cognition.