Where all php is used

What is PHP? Learn All About the Scripting Language

What is PHP, and what is PHP used for exactly? PHP is a server-side scripting programming language that’s used to develop static or dynamic websites, or even web applications.

What does PHP stand for? PHP stands for Hypertext Preprocessor, but you may recognize it as the old acronym for “Personal Home Pages.”

A script is a set of programming instructions interpreted at runtime. A scripting language is responsible for interpreting scripts at runtime. The primary objective of a script is to escalate the performance of various tasks in an application.

But what is PHP programming, and how can you use it? We’ll cover all that today — read on to gather an introduction to PHP and learn all about its uses in the computer world.

What is PHP Programming?

PHP stands for hypertext preprocessor. The PHP programming language is a scripting language used widely across the globe, primarily for web development. You can embed PHP into HTML and work after that too.

Moreover, PHP is server-side, whereas other programming languages like JavaScript are client-side. The major difference between the two is that PHP code is executed on the server that generates HTML, and is sent directly to the client. While the client can see the results by running the script, they cannot access the underlying code.

If you are a beginner, PHP is an extremely simple language for you to learn. It also comprises advanced features for professional programmers. You can start by writing simple scripts and master the PHP programming language gradually.

Now, let’s dive into the syntax of PHP.

Syntax of PHP

PHP syntax is pretty simple. A PHP file can also include HTML or client-side script as JavaScript.

Here is the basic syntax of PHP:

The display screen shows, “I love programming.”

When using PHP, keep the following in mind:

• While not essential, some prior understanding of HTML is ideal before learning the PHP programming language.
• To handle database-powered applications with PHP, use database management systems or DBMS .
• You will need XML or JavaScript to build advanced interactive applications with PHP.

How to Write a Program in PHP

Writing a program in PHP is extremely easy. See the below example:

Let’s move ahead and know why to use PHP.

Why PHP?

As you know, there are a plethora of programming languages available for you to work with as a web developer. So, what makes PHP stand out from the others? Here are a few benefits of using PHP:

• PHP is a free and open-source scripting language.
• PHP is a server-side scripting language . You can install it on the server; however, the clients who request the resources from the server don’t have to install PHP.
• It is cross-platform , allowing you to use it on various operating systems like Windows, macOS, Linux, etc.
• PHP comes with a built-in support system , which means that you can use PHP with various database management systems such as Oracle, Postgres, ODBC, MS, and SQL Server.
• Most web hosting servers support PHP.
• PHP provides you with a huge online community with all kinds of support, including documentation guides and problem-solving posts.
• PHP is easy to learn , especially if you have a basic knowledge of other programming languages.
• Vast text-processing features like PCRE and Perl

In addition, PHP offers a remarkable feature by supporting a wide range of databases. For example, you can use database-specific extensions like MySQL to write a database-enabled web page, use an abstraction layer such as PDO, or even build a connection to a database with the ODBC extension.

Furthermore, while using PHP, you can use both object-oriented programming and procedural programming. You are not just bound to output HTML; rather, you can output any text like XML or XHTML. PHP can auto-generate search files and save them, helping to protect the server-side from forming a cache for the dynamic content.

Now that we know some of PHP’s benefits, let’s get into the PHP extensions.

PHP Extensions

PHP files are saved with the “.php” extension. Some of the earlier PHP file extensions include:

Where is PHP Used?

There are various fields where you can use PHP, and but these are the three most vital areas to use it:

Command-Line Scripting

Several tasks run in the background of a web server besides web applications for the databases. Each task concludes after a designated amount of time. Therefore, every task has its timeline.

Here’s an example of command-line scripting in PHP:

Suppose you have to send an invitation email to your subscribers on a mailing list. You can carry out this task via web scripting. However, the process gets trickier when you reach a few hundred subscribers. And, if there are thousands of subscribers, a web script will only have a couple of minutes for execution, a period known as maximum execution time. At the end of this period, the web server terminates the web script and fails to send the email to a portion of the subscribers.

PHP command-line scripting can resolve this issue:

With command-line scripts, there is no maximum execution time. The scripts can run as long as the server is active.

Hence, with the help of command-line scripting, any kind of time-consuming tasks such as transferring files to another server via FTP or backing up a complete website or database can be done seamlessly.

Server-Side Scripting

Server-side scripting is the most common and frequently used field for PHP. It requires three vital components: a webserver, a web browser, and a PHP parser.

With server-side scripting, you must run the web server with installed PHP. Moreover, you can easily access and run any PHP program output through a web browser.

Writing Desktop Applications

If you want to develop a desktop application and a GUI, PHP may not be the perfect solution for you. However, to access some advanced PHP features, you can use PHP-GTK in your client-side applications to write programs.

PHP-GTK is an extension of PHP. However, you may not find it in the main distribution. To access PHP-GTK, visit the official website .

PHP Data Types and Operators

PHP supports a wide set of data types, such as:

PHP Integer

A non-decimal number within the range of -2,147,483,648 and 2,147,483,647 is an integer data type. A number is an integer only when at least one digit is either positive or negative. Take a look at the below command that takes $z as an integer, with the function var_dump returning the value:

PHP String

A PHP string is any sequence of characters. Here’s the syntax to use a string in PHP:

PHP Float

A floating-point number is any number with a decimal point or a number that’s present in an exponential form.

PHP Array

An array holds multiple values in one variable:

PHP Boolean

A Boolean is used for conditional testing, and it tells you two states:

Now, let’s move on to the PHP operators.

PHP Operators

Operators are primarily used to perform various operations on variables. Different operators in PHP include:

• Logical operators
• Arithmetic operators
• Array operators
• Assignment operators
• Comparison operators

Logical Operators

Logical operators help to combine conditional statements:

Name of the operator

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What can PHP do?

Anything. PHP is mainly focused on server-side scripting, so you can do anything any other CGI program can do, such as collect form data, generate dynamic page content, or send and receive cookies. But PHP can do much more.

• Server-side scripting. This is the most traditional and main target field for PHP. You need three things to make this work: the PHP parser (CGI or server module), a web server and a web browser. You need to run the web server, with a connected PHP installation. You can access the PHP program output with a web browser, viewing the PHP page through the server. All these can run on your home machine if you are just experimenting with PHP programming. See the installation instructions section for more information.
• Command line scripting. You can make a PHP script to run it without any server or browser. You only need the PHP parser to use it this way. This type of usage is ideal for scripts regularly executed using cron (on *nix or Linux) or Task Scheduler (on Windows). These scripts can also be used for simple text processing tasks. See the section about Command line usage of PHP for more information.
• Writing desktop applications. PHP is probably not the very best language to create a desktop application with a graphical user interface, but if you know PHP very well, and would like to use some advanced PHP features in your client-side applications you can also use PHP-GTK to write such programs. You also have the ability to write cross-platform applications this way. PHP-GTK is an extension to PHP, not available in the main distribution. If you are interested in PHP-GTK, visit » its own website.

PHP can be used on all major operating systems, including Linux, many Unix variants (including HP-UX, Solaris and OpenBSD), Microsoft Windows, macOS, RISC OS, and probably others. PHP also has support for most of the web servers today. This includes Apache, IIS, and many others. And this includes any web server that can utilize the FastCGI PHP binary, like lighttpd and nginx. PHP works as either a module, or as a CGI processor.

So with PHP, you have the freedom of choosing an operating system and a web server. Furthermore, you also have the choice of using procedural programming or object-oriented programming (OOP), or a mixture of them both.

With PHP you are not limited to output HTML. PHP’s abilities includes outputting images, PDF files and even Flash movies (using libswf and Ming) generated on the fly. You can also output easily any text, such as XHTML and any other XML file. PHP can autogenerate these files, and save them in the file system, instead of printing it out, forming a server-side cache for your dynamic content.

One of the strongest and most significant features in PHP is its support for a wide range of databases. Writing a database-enabled web page is incredibly simple using one of the database specific extensions (e.g., for mysql), or using an abstraction layer like PDO, or connect to any database supporting the Open Database Connection standard via the ODBC extension. Other databases may utilize cURL or sockets, like CouchDB.

PHP also has support for talking to other services using protocols such as LDAP, IMAP, SNMP, NNTP, POP3, HTTP, COM (on Windows) and countless others. You can also open raw network sockets and interact using any other protocol. PHP has support for the WDDX complex data exchange between virtually all Web programming languages. Talking about interconnection, PHP has support for instantiation of Java objects and using them transparently as PHP objects.

PHP has useful text processing features, which includes the Perl compatible regular expressions (PCRE), and many extensions and tools to parse and access XML documents. PHP standardizes all of the XML extensions on the solid base of libxml2, and extends the feature set adding SimpleXML, XMLReader and XMLWriter support.

And many other interesting extensions exist, which are categorized both alphabetically and by category. And there are additional PECL extensions that may or may not be documented within the PHP manual itself, like » XDebug.

As you can see this page is not enough to list all the features and benefits PHP can offer. Read on in the sections about installing PHP, and see the function reference part for explanation of the extensions mentioned here.

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