PHP

Эта статья о языке сценариев. Чтобы узнать о других значениях, см. PHP (значения) .

PHP

Парадигма	Мультипарадигмальность : императивная , функциональная , объектно-ориентированная , процедурная , рефлексивная.
Разработано	Расмус Лердорф
Разработчик	Команда разработчиков PHP , Zend Technologies , PHP Foundation
Впервые появился	8 июня 1995 г ( 1995-06-08 )
Стабильная версия	8.3.9 / 2 июля 2024 г ( 2024-07-02 )
Дисциплина набора текста	Динамичный , слабый , постепенный
Язык реализации	C (в основном; некоторые компоненты C++ )
ТЫ	Unix-подобные , Windows , macOS , IBM i , OpenVMS , IBM Z
License	dual licensed GNU General Public License version 2 or any later version and PHP License for PHP versions 3.0 or earlier. Only PHP License (most of Zend engine under Zend Engine License) for 3.01x and later versions.
Filename extensions	.php,.phar,.phtml,.pht,.phps
Website	www.php.net
Major implementations
Zend Engine, HHVM, PeachPie, Quercus, Parrot
Influenced by
Perl, C, C++, Java, Tcl, JavaScript
Influenced
Hack, JSP, ASP, React JS
PHP Programming at Wikibooks

PHP — это общего назначения, язык сценариев предназначенный для веб-разработки . Первоначально он был создан датско-канадским программистом Расмусом Лердорфом в 1993 году и выпущен в 1995 году. PHP Эталонная реализация теперь производится PHP Group. Изначально PHP был аббревиатурой Personal Home Page . но теперь это означает рекурсивный инициализм PHP: Hypertext Preprocessor .

PHP code is usually processed on a web server by a PHP interpreter implemented as a module, a daemon or a Common Gateway Interface (CGI) executable. On a web server, the result of the interpreted and executed PHP code—which may be any type of data, such as generated HTML or binary image data—would form the whole or part of an HTTP response. Various web template systems, web content management systems, and web frameworks exist that can be employed to orchestrate or facilitate the generation of that response. Additionally, PHP can be used for many programming tasks outside the web context, such as standalone graphical applications and drone control. PHP-код также может быть выполнен непосредственно из командной строки .

The standard PHP interpreter, powered by the Zend Engine, is free software released under the PHP License. PHP has been widely ported and can be deployed on most web servers on a variety of operating systems and platforms.

The PHP language has evolved without a written formal specification or standard, with the original implementation acting as the de facto standard that other implementations aimed to follow.

W3Techs reports that as of 23 May 2024 (the six months after the PHP 8.3 release), PHP is used by 76.2% of all websites whose programming language could be determined, and 55.1% thereof use PHP 7 which is outdated and known to be insecure.

History

Rasmus Lerdorf, creator of PHP; and Andi Gutmans and Zeev Suraski, creators of the Zend Engine

Early history

PHP development began in 1993 when Rasmus Lerdorf wrote several Common Gateway Interface (CGI) programs in C, which he used to maintain his personal homepage. He extended them to work with web forms and to communicate with databases, and called this implementation "Personal Home Page/Forms Interpreter" or PHP/FI.

An example of the early PHP syntax:

<!--include /text/header.html-->

<!--getenv HTTP_USER_AGENT-->
<!--if substr $exec_result Mozilla-->
  Hey, you are using Netscape!<p>
<!--endif-->

<!--sql database select * from table where user='$username'-->
<!--ifless $numentries 1-->
  Sorry, that record does not exist<p>
<!--endif exit-->
  Welcome <!--$user-->!<p>
  You have <!--$index:0--> credits left in your account.<p>

<!--include /text/footer.html-->

PHP/FI could be used to build simple, dynamic web applications. To accelerate bug reporting and improve the code, Lerdorf initially announced the release of PHP/FI as "Personal Home Page Tools (PHP Tools) version 1.0" on the Usenet discussion group comp.infosystems.www.authoring.cgi on 8 June 1995. This release included basic functionality such as Perl-like variables, form handling, and the ability to embed HTML. By this point, the syntax had changed to resemble that of Perl, but was simpler, more limited, and less consistent.

Early PHP was never intended to be a new programming language; rather, it grew organically, with Lerdorf noting in retrospect: "I don't know how to stop it [...] there was never any intent to write a programming language [...] I have absolutely no idea how to write a programming language [...] I just kept adding the next logical step on the way." A development team began to form and, after months of work and beta testing, officially released PHP/FI 2 in November 1997.

The fact that PHP was not originally designed, but instead was developed organically has led to inconsistent naming of functions and inconsistent ordering of their parameters. In some cases, the function names were chosen to match the lower-level libraries which PHP was "wrapping", while in some very early versions of PHP the length of the function names was used internally as a hash function, so names were chosen to improve the distribution of hash values.

PHP 3 and 4

This is an example of PHP code for the WordPress content management system.

Zeev Suraski and Andi Gutmans rewrote the parser in 1997 and formed the base of PHP 3, changing the language's name to the recursive acronym PHP: Hypertext Preprocessor. Afterwards, public testing of PHP 3 began, and the official launch came in June 1998. Suraski and Gutmans then started a new rewrite of PHP's core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan, Israel.

On 22 May 2000, PHP 4, powered by the Zend Engine 1.0, was released. By August 2008, this branch had reached version 4.4.9. PHP 4 is now no longer under development and nor are any security updates planned to be released.

PHP 5

On 1 July 2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5 included new features such as improved support for object-oriented programming, the PHP Data Objects (PDO) extension (which defines a lightweight and consistent interface for accessing databases), and numerous performance enhancements. In 2008, PHP 5 became the only stable version under development. Late static binding had been missing from previous versions of PHP, and was added in version 5.3.

Many high-profile open-source projects ceased to support PHP 4 in new code from February 5, 2008, because of the GoPHP5 initiative, provided by a consortium of PHP developers promoting the transition from PHP 4 to PHP 5.

Over time, PHP interpreters became available on most existing 32-bit and 64-bit operating systems, either by building them from the PHP source code or by using pre-built binaries. For PHP versions 5.3 and 5.4, the only available Microsoft Windows binary distributions were 32-bit IA-32 builds, requiring Windows 32-bit compatibility mode while using Internet Information Services (IIS) on a 64-bit Windows platform. PHP version 5.5 made the 64-bit x86-64 builds available for Microsoft Windows.

Official security support for PHP 5.6 ended on 31 December 2018.

PHP 6 and Unicode

PHP received mixed reviews due to lacking native Unicode support at the core language level. In 2005, a project headed by Andrei Zmievski was initiated to bring native Unicode support throughout PHP, by embedding the International Components for Unicode (ICU) library, and representing text strings as UTF-16 internally. Since this would cause major changes both to the internals of the language and to user code, it was planned to release this as version 6.0 of the language, along with other major features then in development.

However, a shortage of developers who understood the necessary changes, and performance problems arising from conversion to and from UTF-16, which is rarely used in a web context, led to delays in the project. As a result, a PHP 5.3 release was created in 2009, with many non-Unicode features back-ported from PHP 6, notably namespaces. In March 2010, the project in its current form was officially abandoned, and a PHP 5.4 release was prepared to contain most remaining non-Unicode features from PHP 6, such as traits and closure re-binding. Initial hopes were that a new plan would be formed for Unicode integration, but by 2014 none had been adopted.

PHP 7

During 2014 and 2015, a new major PHP version was developed, PHP 7. The numbering of this version involved some debate among internal developers. While the PHP 6 Unicode experiments had never been released, several articles and book titles referenced the PHP 6 names, which might have caused confusion if a new release were to reuse the name. After a vote, the name PHP 7 was chosen.

The foundation of PHP 7 is a PHP branch that was originally dubbed PHP next generation (phpng). It was authored by Dmitry Stogov, Xinchen Hui and Nikita Popov, and aimed to optimize PHP performance by refactoring the Zend Engine while retaining near-complete language compatibility. By 14 July 2014, WordPress-based benchmarks, which served as the main benchmark suite for the phpng project, showed an almost 100% increase in performance. Changes from phpng make it easier to improve performance in future versions, as more compact data structures and other changes are seen as better suited for a successful migration to a just-in-time (JIT) compiler. Because of the significant changes, the reworked Zend Engine was called Zend Engine 3, succeeding Zend Engine 2 used in PHP 5.

Because of the major internal changes in phpng, it must receive a new major version number of PHP, rather than a minor PHP 5 release, according to PHP's release process. Major versions of PHP are allowed to break backward-compatibility of code and therefore PHP 7 presented an opportunity for other improvements beyond phpng that require backward-compatibility breaks. In particular, it involved the following changes:

• Many fatal or recoverable-level legacy PHP error mechanisms were replaced with modern object-oriented exceptions.
• The syntax for variable dereferencing was reworked to be internally more consistent and complete, allowing the use of the operators ->, [], (),{}, and ::, with arbitrary meaningful left-side expressions.
• Support for legacy PHP 4-style constructor methods was deprecated.
• The behavior of the foreach statement was changed to be more predictable.
• Constructors for the few classes built-in to PHP which returned null upon failure were changed to throw an exception instead, for consistency.
• Several unmaintained or deprecated server application programming interfaces (SAPIs) and extensions were removed from the PHP core, most notably the legacy mysql extension.
• The behavior of the list() operator was changed to remove support for strings.
• Support was removed for legacy ASP-style delimiters <% and %> and <script language="php"> ... </script>.
• An oversight allowing a switch statement to have multiple default clauses was fixed.
• Support for hexadecimal number support in some implicit conversions from strings to number types was removed.
• The left-shift and right-shift operators were changed to behave more consistently across platforms.
• Conversions between floating-point numbers and integers were changed (e.g. infinity changed to convert to zero) and implemented more consistently across platforms.

PHP 7 also included new language features. Most notably, it introduced return type declarations for functions which complement the existing parameter type declarations, and support for the scalar types (integer, float, string, and boolean) in parameter and return type declarations.

PHP 8

PHP 8 was released on 26 November 2020, and is currently the second-most used PHP major version. PHP 8 is a major version and has breaking changes from previous versions. New features and notable changes include:

Just-in-time compilation

Just-in-time compilation is supported in PHP 8.

PHP 8's JIT compiler can provide substantial performance improvements for some use cases, while PHP developer Nikita Popov stated that the performance improvements for most websites will be less substantial than the upgrade from PHP 5 to PHP 7. Substantial improvements are expected more for mathematical-type operations than for common web-development use cases. Additionally, the JIT compiler provides the future potential to move some code from C to PHP, due to the performance improvements for some use cases.

Addition of the match expression

Main article: PHP syntax and semantics § Match expression

PHP 8 introduced the match expression. The match expression is conceptually similar to a switch statement and is more compact for some use cases. Because match is an expression, its result can be assigned to a variable or returned from a function.

Type changes and additions

PHP 8 introduced union types, a new static return type, and a new mixed type.

"Attributes", often referred to as "annotations" in other programming languages, were added in PHP 8, which allow metadata to be added to classes.

throw was changed from being a statement to being an expression. This allows exceptions to be thrown in places that were not previously possible.

Syntax changes and additions

PHP 8 includes changes to allow alternate, more concise, or more consistent syntaxes in a number of scenarios. For example, the nullsafe operator is similar to the null coalescing operator ??, but used when calling methods. The following code snippet will not throw an error if getBirthday() returns null:

$human_readable_date = $user->getBirthday()?->diffForHumans();

Constructor property promotion has been added as "syntactic sugar," allowing class properties to be set automatically when parameters are passed into a class constructor. This reduces the amount of boilerplate code that must be written.

Other minor changes include support for use of ::class on objects, which serves as an alternative for the use of get_class(); non-capturing catches in try-catch blocks; variable syntax tweaks to resolve inconsistencies; support for named arguments; and support for trailing commas in parameter lists, which adds consistency with support for trailing commas in other contexts, such as in arrays.

Standard library changes and additions

• Weak maps were added in PHP 8. A WeakMap holds references to objects, but these references do not prevent such objects from being garbage collected. This can provide performance improvements in scenarios where data is being cached; this is of particular relevance for object–relational mappings (ORM).
• Various adjustments to interfaces, such as adding support for creating DateTime objects from interfaces, and the addition of a Stringable interface that can be used for type hinting.
• Various new functions including str_contains(), str_starts_with(), and str_ends_with(); fdiv(); get_debug_type(); and get_resource_id()
• Object implementation of token_get_all()

Additional changes

• Type annotations were also added into PHP's C source code itself to allow internal functions and methods to have "complete type information in reflection."
• Inheritance with private methods
• Abstract methods in traits improvements

PHP 8.1

PHP 8.1 was released on November 25, 2021. It added support for enumerations (also called "enums"), declaring properties as readonly (which prevents modification of the property after initialization), and array unpacking with string keys. The new never type can be used to indicate that a function does not return.

PHP 8.2

PHP 8.2 was released on December 8, 2022. New in this release are readonly classes (whose instance properties are implicitly readonly), disjunctive normal form (DNF) types, and the random extension, which provides a pseudorandom number generator with an object-oriented API, Sensitive Parameter value redaction, and a ton of other features.

Release history

Version	Release date	Supported until	Notes
Old version, no longer maintained: 1.0	8 June 1995		Officially called "Personal Home Page Tools (PHP Tools)". This is the first use of the name "PHP".
Old version, no longer maintained: 2.0	1 November 1997		Officially called "PHP/FI 2.0". This is the first release that could actually be characterised as PHP, being a standalone language with many features that have endured to the present day.
Old version, no longer maintained: 3.0	6 June 1998	20 October 2000	Development moves from one person to multiple developers. Zeev Suraski and Andi Gutmans rewritten the base for this version.
Old version, no longer maintained: 4.0	22 May 2000	23 June 2001	Added more advanced two-stage parse/execute tag-parsing system called the Zend engine.
Old version, no longer maintained: 4.1	10 December 2001	12 March 2002	Introduced "superglobals" ($_GET, $_POST, $_SESSION, etc.)
Old version, no longer maintained: 4.2	22 April 2002	6 September 2002	Disabled register_globals by default. Data received over the network is not inserted directly into the global namespace anymore, closing possible security holes in applications.
Old version, no longer maintained: 4.3	27 December 2002	31 March 2005	Introduced the command-line interface (CLI), to supplement the CGI.
Old version, no longer maintained: 4.4	11 July 2005	7 August 2008	Fixed a memory corruption bug, which required breaking binary compatibility with extensions compiled against PHP version 4.3.x.
Old version, no longer maintained: 5.0	13 July 2004	5 September 2005	Zend Engine II with a new object model.
Old version, no longer maintained: 5.1	24 November 2005	24 August 2006	Performance improvements with the introduction of compiler variables in re-engineered PHP Engine. Added PHP Data Objects (PDO) as a consistent interface for accessing databases.
Old version, no longer maintained: 5.2	2 November 2006	6 January 2011	Enabled the filter extension by default. Native JSON support.
Old version, no longer maintained: 5.3	30 June 2009	14 August 2014	Namespace support; late static bindings, jump label (limited goto), anonymous functions, closures, PHP archives (phar), garbage collection for circular references, improved Windows support, sqlite3, mysqlnd as a replacement for libmysql as the underlying library for the extensions that work with MySQL, fileinfo as a replacement for mime_magic for better MIME support, the Internationalization extension, and deprecation of ereg extension.
Old version, no longer maintained: 5.4	1 March 2012	3 September 2015	Trait support, short array syntax support. Removed items: register_globals, safe_mode, allow_call_time_pass_reference, session_register(), session_unregister() and session_is_registered(). Built-in web server. Several improvements to existing features, performance and reduced memory requirements.
Old version, no longer maintained: 5.5	20 June 2013	10 July 2016	Support for generators, finally blocks for exceptions handling, OpCache (based on Zend Optimizer+) bundled in official distribution.
Old version, no longer maintained: 5.6	28 August 2014	31 December 2018	Constant scalar expressions, variadic functions, argument unpacking, new exponentiation operator, extensions of the use statement for functions and constants, new phpdbg debugger as a SAPI module, and other smaller improvements.
6.x	Not released	—	Abandoned version of PHP that planned to include native Unicode support.
Old version, no longer maintained: 7.0	3 December 2015	10 January 2019	Zend Engine 3 (performance improvements and 64-bit integer support on Windows), uniform variable syntax, AST-based compilation process, added Closure::call(), bitwise shift consistency across platforms, ?? (null coalesce) operator, Unicode code point escape syntax, return type declarations, scalar type (integer, float, string and boolean) declarations, <=> "spaceship" three-way comparison operator, generator delegation, anonymous classes, simpler and more consistently available CSPRNG API, replacement of many remaining internal PHP "errors" with the more modern exceptions, and shorthand syntax for importing multiple items from a namespace.
Old version, no longer maintained: 7.1	1 December 2016	1 December 2019	iterable type, nullable types, void return type, class constant visibility modifiers, short list syntax, multi-catch
Old version, no longer maintained: 7.2	30 November 2017	30 November 2020	Object parameter and return type declaration, libsodium extension, abstract method overriding, parameter type widening
Old version, no longer maintained: 7.3	6 December 2018	6 December 2021	Flexible Heredoc and Nowdoc syntax, support for reference assignment and array deconstruction with list(), PCRE2 support, hrtime function
Old version, no longer maintained: 7.4	28 November 2019	28 November 2022	Typed properties 2.0, preloading, null-coalescing assignment operator, improve openssl_random_pseudo_bytes, weak references, foreign function interface (FFI), always available hash extension, password hash registry, multibyte string splitting, reflection for references, unbundle ext/wddx, new custom object serialization mechanism
Old version, no longer maintained: 8.0	26 November 2020	26 November 2023	Just-In-Time (JIT) compilation, arrays starting with a negative index, stricter/saner language semantics (validation for abstract trait methods), saner string to number comparisons, saner numeric strings, TypeError on invalid arithmetic/bitwise operators, reclassification of various engine errors, consistent type errors for internal functions, fatal error for incompatible method signatures), locale-independent float to string conversion, variable syntax tweaks, attributes, named arguments, match expression, constructor property promotion, union types, mixed type, static return type, nullsafe operator, non-capturing catches, throw expression, JSON extension is always available.
Older version, yet still maintained: 8.1	25 November 2021	31 December 2025	Explicit octal integer literal notation, enumerations, read-only properties, first-class callable syntax, new in initializers, pure intersection types, never return type, final class constraints, fibers
Older version, yet still maintained: 8.2	8 December 2022	31 December 2026	Readonly classes, null, false, and true as stand-alone types, locale-independent case conversion, disjunctive normal form types, constants in traits
Current stable version: 8.3	23 November 2023	31 December 2027	Typed class constants, dynamic class constant fetch, #[\Override] attribute, deep-cloning of read-only properties, new json_validate function, randomizer additions, the command-line linter supports multiple files
Future release: 8.4	21 November 2024	31 December 2028
Legend: Old version Older version, still maintained Latest version Latest preview version Future release

Beginning on 28 June 2011, the PHP Development Team implemented a timeline for the release of new versions of PHP. Under this system, at least one release should occur every month. Once per year, a minor release should occur which may include new features. Every minor release should at least be supported for two years with security and bug fixes, followed by at least one year of only security fixes, for a total of a three-year release process for every minor release. No new features, unless small and self-contained, are to be introduced into a minor release during the three-year release process.

Mascot

The elePHPant, PHP mascot

The mascot of the PHP project is the elePHPant, a blue elephant with the PHP logo on its side, designed by Vincent Pontier in 1998. "The (PHP) letters were forming the shape of an elephant if viewed in a sideways angle." The elePHPant is sometimes differently coloured when in plush toy form.

Many variations of this mascot have been made over the years. Only the elePHPants based on the original design by Vincent Pontier are considered official by the community. These are collectable and some of them are extremely rare.

Syntax

Main article: PHP syntax and semantics

A "Hello, World" application in PHP 7.4 running on its built-in development server

The following "Hello, World!" program is written in PHP code embedded in an HTML document:

<!DOCTYPE html>
<html>
    <head>
        <title>PHP "Hello, World!" program</title>
    </head>
    <body>
        <p><?= 'Hello, World!' ?></p>
    </body>
</html>

However, as no requirement exists for PHP code to be embedded in HTML, the simplest version of Hello, World! may be written like this, with the closing tag ?> omitted as preferred in files containing pure PHP code.

<?php echo 'Hello, World!';

The PHP interpreter only executes PHP code within its delimiters. Anything outside of its delimiters is not processed by PHP, although the non-PHP text is still subject to control structures described in PHP code. The most common delimiters are <?php to open and ?> to close PHP sections. The shortened form <? also exists. This short delimiter makes script files less portable since support for them can be disabled in the local PHP configuration and it is therefore discouraged. Conversely, there is no recommendation against the echo short tag <?=. Prior to PHP 5.4.0, this short syntax for echo only works with the short_open_tag configuration setting enabled, while for PHP 5.4.0 and later it is always available. The purpose of all these delimiters is to separate PHP code from non-PHP content, such as JavaScript code or HTML markup. So the shortest "Hello, World!" program written in PHP is:

<?='Hello, World!';

The first form of delimiters, <?php and ?>, in XHTML and other XML documents, creates correctly formed XML processing instructions. This means that the resulting mixture of PHP code and other markups in the server-side file is itself well-formed XML.

Variables are prefixed with a dollar symbol, and a type does not need to be specified in advance. PHP 5 introduced type declarations that allow functions to force their parameters to be objects of a specific class, arrays, interfaces or callback functions. However, before PHP 7, type declarations could not be used with scalar types such as integers or strings.

Below is an example of how PHP variables are declared and initialized.

<?php
    $name = 'John';  // variable of string type being declared and initialized
    $age = 18;       // variable of integer type being declared and initialized
    $height = 5.3;   // variable of double type being declared and initialized
    echo $name . ' is ' . $height . "m tall\n"; // concatenating variables and strings
    echo "$name is $age years old."; // interpolating variables to string
?>

Unlike function and class names, variable names are case-sensitive. Both double-quoted ("") and heredoc strings provide the ability to interpolate a variable's value into the string. PHP treats newlines as whitespace in the manner of a free-form language, and statements are terminated by a semicolon. PHP has three types of comment syntax: /* */ marks block and inline comments; // or # are used for one-line comments. The echo statement is one of several facilities PHP provides to output text.

In terms of keywords and language syntax, PHP is similar to C-style syntax. if conditions, for and while loops and function returns are similar in syntax to languages such as C, C++, C#, Java and Perl.

Data types

PHP is loosely typed. It stores integers in a platform-dependent range, either as a 32, 64 or 128-bit signed integer equivalent to the C-language long type. Unsigned integers are converted to signed values in certain situations, which is different behaviour to many other programming languages. Integer variables can be assigned using decimal (positive and negative), octal, hexadecimal, and binary notations.

Floating-point numbers are also stored in a platform-specific range. They can be specified using floating-point notation, or two forms of scientific notation. PHP has a native Boolean type that is similar to the native Boolean types in Java and C++. Using the Boolean type conversion rules, non-zero values are interpreted as true and zero as false, as in Perl and C++.

The null data type represents a variable that has no value; NULL is the only allowed value for this data type.

Variables of the "resource" type represent references to resources from external sources. These are typically created by functions from a particular extension, and can only be processed by functions from the same extension; examples include file, image, and database resources.

Arrays can contain elements of any type that PHP can handle, including resources, objects, and even other arrays. Order is preserved in lists of values and in hashes with both keys and values, and the two can be intermingled. PHP also supports strings, which can be used with single quotes, double quotes, nowdoc or heredoc syntax.

The Standard PHP Library (SPL) attempts to solve standard problems and implements efficient data access interfaces and classes.

Functions

PHP defines a large array of functions in the core language and many are also available in various extensions; these functions are well documented online PHP documentation. However, the built-in library has a wide variety of naming conventions and associated inconsistencies, as described under history above.

Custom functions may be defined by the developer:

function myAge(int $birthYear): string
{
    // calculate the age by subtracting the birth year from the current year.
    $yearsOld = date('Y') - $birthYear;

    // return the age in a descriptive string.
    return $yearsOld . ($yearsOld == 1 ? ' year' : ' years');
}

echo 'I am currently ' . myAge(1995) . ' old.';

As of 2024, the output of the above sample program is "I am currently 29 years old."

In lieu of function pointers, functions in PHP can be referenced by a string containing their name. In this manner, normal PHP functions can be used, for example, as callbacks or within function tables. User-defined functions may be created at any time without being prototyped. Functions may be defined inside code blocks, permitting a run-time decision as to whether or not a function should be defined. There is a function_exists function that determines whether a function with a given name has already been defined. Function calls must use parentheses, with the exception of zero-argument class constructor functions called with the PHP operator new, in which case parentheses are optional.

Since PHP 4.0.1 create_function(), a thin wrapper around eval(), allowed normal PHP functions to be created during program execution; it was deprecated in PHP 7.2 and removed in PHP 8.0 in favor of syntax for anonymous functions or "closures" that can capture variables from the surrounding scope, which was added in PHP 5.3. Shorthand arrow syntax was added in PHP 7.4:

function getAdder($x) {
    return fn($y) => $x + $y;
}

$adder = getAdder(8);
echo $adder(2);  // prints "10"

In the example above, getAdder() function creates a closure using passed argument $x, which takes an additional argument $y, and returns the created closure to the caller. Such a function is a first-class object, meaning that it can be stored in a variable, passed as a parameter to other functions, etc.

Unusually for a dynamically typed language, PHP supports type declarations on function parameters, which are enforced at runtime. This has been supported for classes and interfaces since PHP 5.0, for arrays since PHP 5.1, for "callables" since PHP 5.4, and scalar (integer, float, string and boolean) types since PHP 7.0. PHP 7.0 also has type declarations for function return types, expressed by placing the type name after the list of parameters, preceded by a colon. For example, the getAdder function from the earlier example could be annotated with types like so in PHP 7:

function getAdder(int $x): Closure
{
    return fn(int $y): int => $x + $y;
}

$adder = getAdder(8);
echo $adder(2); // prints "10"
echo $adder(null); // throws an exception because an incorrect type was passed
$adder = getAdder([]); // would also throw an exception

By default, scalar type declarations follow weak typing principles. So, for example, if a parameter's type is int, PHP would allow not only integers, but also convertible numeric strings, floats or Booleans to be passed to that function, and would convert them. However, PHP 7 has a "strict typing" mode which, when used, disallows such conversions for function calls and returns within a file.

PHP objects

Basic object-oriented programming functionality was added in PHP 3 and improved in PHP 4. This allowed for PHP to gain further abstraction, making creative tasks easier for programmers using the language. Object handling was completely rewritten for PHP 5, expanding the feature set and enhancing performance. In previous versions of PHP, objects were handled like value types. The drawback of this method was that code had to make heavy use of PHP's "reference" variables if it wanted to modify an object it was passed rather than creating a copy of it. In the new approach, objects are referenced by handle, and not by value.

PHP 5 introduced private and protected member variables and methods, along with abstract classes, final classes, abstract methods, and final methods. It also introduced a standard way of declaring constructors and destructors, similar to that of other object-oriented languages such as C++, and a standard exception handling model. Furthermore, PHP 5 added interfaces and allowed for multiple interfaces to be implemented. There are special interfaces that allow objects to interact with the runtime system. Objects implementing ArrayAccess can be used with array syntax and objects implementing Iterator or IteratorAggregate can be used with the foreach language construct. There is no virtual table feature in the engine, so static variables are bound with a name instead of a reference at compile time.

If the developer creates a copy of an object using the reserved word clone, the Zend engine will check whether a __clone() method has been defined. If not, it will call a default __clone() which will copy the object's properties. If a __clone() method is defined, then it will be responsible for setting the necessary properties in the created object. For convenience, the engine will supply a function that imports the properties of the source object, so the programmer can start with a by-value replica of the source object and only override properties that need to be changed.

The visibility of PHP properties and methods is defined using the keywords public, private, and protected. The default is public, if only var is used; var is a synonym for public. Items declared public can be accessed everywhere. protected limits access to inherited classes (and to the class that defines the item). private limits visibility only to the class that defines the item. Objects of the same type have access to each other's private and protected members even though they are not the same instance.

Example

The following is a basic example of object-oriented programming in PHP 8:

<?php

abstract class User
{
    protected string $name;

    public function __construct(string $name)
    {
        // make first letter uppercase and the rest lowercase
        $this->name = ucfirst(strtolower($name));
    }

    public function greet(): string
    {
        return "Hello, my name is " . $this->name;
    }

    abstract public function job(): string;
}

class Student extends User
{
    public function __construct(string $name, private string $course)
    {
        parent::__construct($name);
    }

    public function job(): string
    {
        return "I learn " . $this->course;
    }
}

class Teacher extends User
{
    public function __construct(string $name, private array $teachingCourses)
    {
        parent::__construct($name);
    }

    public function job(): string
    {
        return "I teach " . implode(", ", $this->teachingCourses);
    }
}

$students = [
    new Student("Alice", "Computer Science"),
    new Student("Bob", "Computer Science"),
    new Student("Charlie", "Business Studies"),
];

$teachers = [
    new Teacher("Dan", ["Computer Science", "Information Security"]),
    new Teacher("Erin", ["Computer Science", "3D Graphics Programming"]),
    new Teacher("Frankie", ["Online Marketing", "Business Studies", "E-commerce"]),
];

foreach ([$students, $teachers] as $users) {
    echo $users[0]::class . "s:\n";

    array_walk($users, function (User $user) {
        echo "{$user->greet()}, {$user->job()}\n";
    });
}

This program outputs the following:

Students:
Hello, my name is Alice, I learn Computer Science
Hello, my name is Bob, I learn Computer Science
Hello, my name is Charlie, I learn Business Studies
Teachers:
Hello, my name is Dan, I teach Computer Science, Information Security
Hello, my name is Erin, I teach Computer Science, 3D Graphics Programming
Hello, my name is Frankie, I teach Online Marketing, Business Studies, E-commerce

Implementations

The only complete PHP implementation is the original, known simply as PHP. It is the most widely used and is powered by the Zend Engine. To disambiguate it from other implementations, it is sometimes unofficially called "Zend PHP". The Zend Engine compiles PHP source code on-the-fly into an internal format that it can execute, thus it works as an interpreter. It is also the "reference implementation" of PHP, as PHP has no formal specification, and so the semantics of Zend PHP define the semantics of PHP. Due to the complex and nuanced semantics of PHP, defined by how Zend works, it is difficult for competing implementations to offer complete compatibility.

PHP's single-request-per-script-execution model, and the fact that the Zend Engine is an interpreter, leads to inefficiency; as a result, various products have been developed to help improve PHP performance. In order to speed up execution time and not have to compile the PHP source code every time the web page is accessed, PHP scripts can also be deployed in the PHP engine's internal format by using an opcode cache, which works by caching the compiled form of a PHP script (opcodes) in shared memory to avoid the overhead of parsing and compiling the code every time the script runs. An opcode cache, Zend Opcache, is built into PHP since version 5.5. Another example of a widely used opcode cache is the Alternative PHP Cache (APC), which is available as a PECL extension.

While Zend PHP is still the most popular implementation, several other implementations have been developed. Some of these are compilers or support JIT compilation, and hence offer performance benefits over Zend PHP at the expense of lacking full PHP compatibility. Alternative implementations include the following:

• HHVM (HipHop Virtual Machine) – developed at Facebook and available as open source, it converts PHP code into a high-level bytecode (commonly known as an intermediate language), which is then translated into x86-64 machine code dynamically at runtime by a just-in-time (JIT) compiler, resulting in up to 6× performance improvements. However, since version 7.2 Zend has outperformed HHVM, and HHVM 3.24 is the last version to officially support PHP.
  • HipHop – developed at Facebook and available as open source, it transforms the PHP scripts into C++ code and then compiles the resulting code, reducing the server load up to 50%. In early 2013, Facebook deprecated it in favour of HHVM due to multiple reasons, including deployment difficulties and lack of support for the whole PHP language, including the create_function() and eval() constructs.
• Parrot – a virtual machine designed to run dynamic languages efficiently; the cross-translator Pipp transforms the PHP source code into the Parrot intermediate representation, which is then translated into the Parrot's bytecode and executed by the virtual machine.
• PeachPie – a second-generation compiler to .NET Common Intermediate Language (CIL) bytecode, built on the Roslyn platform; successor of Phalanger, sharing several architectural components
• Phalanger – compiles PHP into .Net Common Intermediate Language bytecode; predecessor of PeachPie
• Quercus – compiles PHP into Java bytecode

Licensing

Main article: PHP License

PHP is free software released under the PHP License, which stipulates that:

Products derived from this software may not be called "PHP", nor may "PHP" appear in their name, without prior written permission from [email protected]. You may indicate that your software works in conjunction with PHP by saying "Foo for PHP" instead of calling it "PHP Foo" or "phpfoo".

This restriction on the use of "PHP" makes the PHP License incompatible with the GNU General Public License (GPL), while the Zend License is incompatible due to an advertising clause similar to that of the original BSD license.

Development and community

PHP includes various free and open-source libraries in its source distribution or uses them in resulting PHP binary builds. PHP is fundamentally an Internet-aware system with built-in modules for accessing File Transfer Protocol (FTP) servers and many database servers, including PostgreSQL, MySQL, Microsoft SQL Server and SQLite (which is an embedded database), LDAP servers, and others. Numerous functions are familiar to C programmers, such as those in the stdio family, are available in standard PHP builds.

PHP allows developers to write extensions in C to add functionality to the PHP language. PHP extensions can be compiled statically into PHP or loaded dynamically at runtime. Numerous extensions have been written to add support for the Windows API, process management on Unix-like operating systems, multibyte strings (Unicode), cURL, and several popular compression formats. Other PHP features made available through extensions include integration with Internet Relay Chat (IRC), dynamic generation of images and Adobe Flash content, PHP Data Objects (PDO) as an abstraction layer used for accessing databases, and even speech synthesis. Some of the language's core functions, such as those dealing with strings and arrays, are also implemented as extensions. The PHP Extension Community Library (PECL) project is a repository for extensions to the PHP language.

Some other projects, such as Zephir, provide the ability for PHP extensions to be created in a high-level language and compiled into native PHP extensions. Such an approach, instead of writing PHP extensions directly in C, simplifies the development of extensions and reduces the time required for programming and testing.

By December 2018 the PHP Group consisted of ten people: Thies C. Arntzen, Stig Bakken, Shane Caraveo, Andi Gutmans, Rasmus Lerdorf, Sam Ruby, Sascha Schumann, Zeev Suraski, Jim Winstead, and Andrei Zmievski.

Zend Technologies provides a PHP Certification based on PHP 7 exam (and previously based on PHP 5.5) for programmers to become certified PHP developers.

The PHP Foundation

PHP

Формирование	22 ноября 2021 г ( 22.11.2021 )
Основатель	Automattic , Laravel , Acquia , Zend , Частный упаковщик, Symfony , Craft CMS, Tideways, PrestaShop , JetBrains
Веб-сайт	https://thephp.foundation

26 ноября 2021 года блог JetBrains объявил о создании The PHP Foundation, который будет спонсировать проектирование и разработку PHP.

Год	фиксирует	Отзывы	RFC
2022	683	283	8
2023	784	702	17

Фонд нанимает «Основных разработчиков» для работы над основным репозиторием языка PHP. Член правления фонда Роман Пронский заявил, что они намерены выплачивать застройщикам "рыночные зарплаты".

Реакция на фонд в основном была положительной: фонд хвалили за лучшую поддержку языка и помощь в прекращении падения популярности языка. Однако его также критиковали за добавление критических изменений в второстепенные версии PHP, например, в PHP 8.2, где инициализация членов класса вне исходной области действия класса приводила к ошибкам обесценивания. эти изменения повлияли на ряд проектов с открытым исходным кодом, включая WordPress .

Германии Суверенный технологический фонд выделил более 200 000 евро на поддержку PHP Foundation.

Установка и настройка

Пример вывода функции phpinfo() в PHP 7.1

Существует два основных способа добавить поддержку PHP на веб-сервер — в виде собственного модуля веб-сервера или в виде исполняемого файла CGI. PHP имеет прямой интерфейс модуля, называемый интерфейсом программирования серверных приложений (SAPI), который поддерживается многими веб-серверами, включая HTTP-сервер Apache , Microsoft IIS и веб-сервер iPlanet . Некоторые другие веб-серверы, такие как OmniHTTPd, поддерживают интерфейс программирования приложений интернет-сервера (ISAPI), который представляет собой интерфейс модуля веб-сервера Microsoft . Если PHP не поддерживает модули веб-сервера, его всегда можно использовать в качестве процессора Common Gateway Interface (CGI) или FastCGI ; в этом случае веб-сервер настроен на использование исполняемого файла CGI PHP для обработки всех запросов к файлам PHP.

PHP-FPM (FastCGI Process Manager) — это альтернативная реализация FastCGI для PHP, входящая в состав официального дистрибутива PHP, начиная с версии 5.3.3. По сравнению со старой реализацией FastCGI, она содержит некоторые дополнительные функции, в основном полезные для сильно нагруженных веб-серверов.

При использовании PHP для сценариев командной строки интерфейса командной строки необходим исполняемый файл CLI (CLI) PHP. PHP поддерживает интерфейс программирования приложений сервера (SAPI), начиная с PHP 4.3.0. Основное внимание в этом SAPI уделяется разработке оболочки приложений с использованием PHP. Между CLI SAPI и другими SAPI существует немало различий, хотя во многом они имеют одинаковое поведение.

PHP имеет прямой интерфейс модуля под названием SAPI для различных веб-серверов; в случае PHP 5 и Apache 2.0 в Windows он предоставляется в виде файла DLL с именем php5apache2.dll , это модуль, который, помимо других функций, обеспечивает интерфейс между PHP и веб-сервером, реализованный в форме, понятной серверу. Эта форма известна как SAPI.

Существуют разные типы SAPI для различных расширений веб-сервера. Например, в дополнение к перечисленным выше, другие SAPI для языка PHP включают интерфейс Common Gateway и интерфейс командной строки.

PHP также можно использовать для написания настольных приложений с графическим пользовательским интерфейсом (GUI) с помощью расширения PHP-GTK . PHP-GTK не включен в официальный дистрибутив PHP. и как расширение его можно использовать только с версиями PHP 5.1.0 и новее. Самый распространенный способ установки PHP-GTK — это его компиляция из исходного кода.

Когда PHP устанавливается и используется в облачных средах, комплекты разработки программного обеспечения (SDK) для использования функций, специфичных для облака. предоставляются Например:

• Amazon Web Services предоставляет AWS SDK для PHP
• Microsoft Azure можно использовать с Windows Azure SDK для PHP.

Поддерживаются многочисленные параметры конфигурации, влияющие как на основные функции PHP, так и на расширения. Конфигурационный файл php.ini ищется в разных местах, в зависимости от способа использования PHP. Файл конфигурации разделен на различные разделы, хотя некоторые параметры конфигурации также можно установить в конфигурации веб-сервера.

Использовать

Общий обзор программного пакета LAMP, показанный здесь вместе со Squid.

PHP — это язык сценариев общего назначения, который особенно подходит для на стороне сервера веб-разработки , и в этом случае PHP обычно запускается на веб-сервере . Любой код PHP в запрошенном файле выполняется средой выполнения PHP, обычно для создания динамического содержимого веб-страницы или динамических изображений, используемых на веб-сайтах или в других местах. Его также можно использовать для сценариев командной строки и (GUI) на стороне клиента с графическим интерфейсом пользователя приложений . PHP можно развернуть на большинстве веб-серверов, во многих операционных системах и платформах , а также использовать со многими системами управления реляционными базами данных (СУБД). Большинство провайдеров веб-хостинга поддерживают PHP для использования своими клиентами. Он доступен бесплатно, и PHP Group предоставляет пользователям полный исходный код для создания, настройки и расширения для собственного использования.

Динамическая веб-страница: пример серверного сценария (PHP и MySQL)

Первоначально разработанный для создания динамических веб-страниц , PHP теперь фокусируется в основном на написании сценариев на стороне сервера . и он похож на другие серверные языки сценариев, которые передают динамический контент от веб-сервера клиенту , такие как Python , Microsoft от ASP.NET , Sun Microsystems от JavaServer Pages , и mod_perl. PHP также привлек внимание к разработке множества программных платформ , которые предоставляют строительные блоки и структуру проектирования для ускорения разработки приложений (RAD). Некоторые из них включают PRADO , CakePHP , Symfony , CodeIgniter , Laravel , Yii Framework , Phalcon и Laminas , предлагающие функции, аналогичные другим веб-фреймворкам .

Архитектура LAMP стала популярной в веб-индустрии как способ развертывания веб-приложений. PHP обычно используется как P в этом пакете наряду с Linux , Apache и MySQL , хотя P может также относиться к Python , Perl или их смеси. Аналогичные пакеты WAMP и MAMP также доступны для Windows и macOS , где первая буква обозначает соответствующую операционную систему. Хотя и PHP, и Apache включены в базовую установку macOS, пользователям этих пакетов нужен более простой механизм установки, который легче поддерживать в актуальном состоянии.

Для конкретных и более сложных сценариев использования PHP предлагает четко определенный и документированный способ написания пользовательских расширений на C или C++ . Помимо расширения самого языка в виде дополнительных библиотек , расширения предоставляют возможность повысить скорость выполнения там, где это критично, и есть возможности для улучшений за счет использования настоящего компилируемого языка . PHP также предлагает четко определенные способы встраивания в другие программные проекты. Таким образом, PHP можно легко использовать в качестве внутреннего языка сценариев проекта для другого проекта, обеспечивая при этом тесный интерфейс с конкретными внутренними структурами данных .

PHP получил неоднозначные отзывы из-за отсутствия поддержки многопоточности на уровне ядра языка. хотя использование потоков стало возможным благодаря расширению PECL «pthreads» .

интерфейс командной строки, php-cli и два скриптовых механизма ActiveX Windows Script Host для PHP. Были созданы

Статистика популярности и использования

PHP используется для систем управления веб-контентом, включая MediaWiki , WordPress , Джумла , Друпал , Мудл , eZ Publish , eZ Platform и SilverStripe .

По состоянию на январь 2013 г. PHP использовался на более чем 240 миллионах веб-сайтов (39% из выбранных) и был установлен на 2,1 миллиона веб-серверов .

По состоянию на 23 июля 2024 г. (через восемь месяцев после выпуска PHP 8.3) PHP используется в качестве серверного языка программирования на 76,1% веб-сайтов, язык которых можно определить; PHP 7 является наиболее используемой версией языка: 53% веб-сайтов, использующих PHP, используют эту версию, 32,5% используют PHP 8, 14,3% используют PHP 5 и 0,2% используют PHP 4.

PHP 8:
32.5%

PHP 7:
53%

PHP 5+PHP 4:
14.3%+0.2%

Доля использования версий PHP на 23 июля 2024 г.:
через восемь месяцев после выпуска PHP 8.3

  PHP 8.3: 6,00% от PHP 8 (1,95%)

  PHP 8.2: 20,3% от PHP 8 (6,60%)

  PHP 8.1: 43,3% от PHP 8 (14,07%)

  PHP 8.0: 30,4% от PHP 8 (9,88%)

  PHP 7.4: 70,9% PHP 7 (37,58%)

  PHP 7.3: 12,3% от PHP 7 (6,52%)

  PHP 7.2: 9,00% от PHP 7 (4,77%)

  PHP 7.1: 3,80% от PHP 7 (2,01%)

  PHP 7.0: 4,10% от PHP 7 (2,17%)

  PHP 5.6: 53,9% от PHP 5 (7,7077%)

  PHP 5.5: 8,40% от PHP 5 (1,2012%)

  PHP 5.4: 15,5% от PHP 5 (2,2165%)

  PHP 5.3: 14,9% от PHP 5 (2,1307%)

  PHP 5.2: 6,90% от PHP 5 (0,9867%)

  PHP 5.1: 0,40% от PHP 5 (0,0572%)

  PHP 5.0: 0,10% от PHP 5 (0,0143%)

  PHP 4.4: 78,7% от PHP 4 (0,1574%)

  PHP 4.3: 18,0% от PHP 4 (0,0360%)

  PHP 4.2: 2,10% от PHP 4 (0,0042%)

  PHP 4.1: 0,80% от PHP 4 (0,0016%)

  PHP 4.0: 0,40% от PHP 4 (0,0008%)

Безопасность

В 2019 году 11% всех уязвимостей, перечисленных в Национальной базе данных уязвимостей, были связаны с PHP; исторически около 30% всех уязвимостей, перечисленных в этой базе данных с 1996 года, связаны с PHP. Технические недостатки безопасности самого языка или его основных библиотек встречаются нечасто (22 в 2009 году, около 1% от общего числа, хотя PHP применим примерно к 20% перечисленных программ). Признавая, что программисты допускают ошибки, некоторые языки включают проверку на наличие ошибок , чтобы автоматически обнаруживать отсутствие проверки ввода , что вызывает множество проблем. Такая функция разрабатывается для PHP, но в прошлом его включение в релиз несколько раз отклонялось.

Существуют исправления расширенной защиты, такие как Suhosin и Hardening -Patch, специально разработанные для сред веб-хостинга.

Исторически сложилось так, что старые версии PHP имели некоторые параметры конфигурации и значения по умолчанию для таких настроек времени выполнения, что делало некоторые приложения PHP уязвимыми к проблемам с безопасностью. Среди них magic_quotes_gpc и register_globals директивы конфигурации были наиболее известны; последний превратил любые параметры URL-адреса в переменные PHP, открывая путь для серьезных уязвимостей безопасности, позволяя злоумышленнику установить значение любой неинициализированной глобальной переменной и помешать выполнению PHP-скрипта. Поддержка настроек « волшебных кавычек » и «регистрации глобальных переменных» устарела, начиная с PHP 5.3.0, и удалена из PHP 5.4.0.

Другой пример потенциальной уязвимости настроек времени выполнения — невозможность отключить выполнение PHP (например, с помощью engine директива конфигурации) для каталога, в котором хранятся загруженные файлы; его включение может привести к выполнению вредоносного кода, встроенного в загруженные файлы. Лучше всего либо найти каталог изображений за пределами корня документа, доступного веб-серверу, и обслуживать его через промежуточный скрипт, либо отключить выполнение PHP для каталога, в котором хранятся загруженные файлы.

Кроме того, включение динамической загрузки расширений PHP (через enable_dl директива конфигурации) в среде общего веб-хостинга может привести к проблемам с безопасностью.

Неявные преобразования типов , в результате которых разные значения рассматриваются как равные, иногда вопреки намерениям программиста, могут привести к проблемам безопасности. Например, результат сравнения '0e1234' == '0' является true, поскольку строки, которые можно анализировать как числа, преобразуются в числа; в этом случае первое сравниваемое значение рассматривается как экспоненциальное обозначение, имеющее значение ( 0 × 10 ¹²³⁴ ), что равно нулю. Подобные ошибки приводили к уязвимостям аутентификации на форуме Simple Machines , Опечатка3 и phpBB при MD5 хешей паролей сравнении . Рекомендуемый способ — использовать hash_equals() (для безопасности атаки по времени ), strcmp или оператор идентификации ( ===), как '0e1234' === '0' приводит к false.

В анализе более 170 000 дефейсов веб-сайтов , опубликованном Zone-H в 2013 году , наиболее часто (53%) используемым методом была эксплуатация уязвимости включения файлов , в основном связанная с небезопасным использованием конструкций языка PHP. include, require, и allow_url_fopen.

Настоятельно рекомендуется перейти на PHP 8.1 или более позднюю версию и использовать random_int() вместо rand() или mt_rand(), поскольку последние функции не являются криптографически безопасными. Существует две атаки, которые можно осуществить на источники энтропии PHP: «начальная атака» и «атака восстановления состояния». стоимостью 250 долларов По состоянию на 2012 год графический процессор может выполнять до 2 ³⁰ Вычисления MD5 в секунду, а графический процессор стоимостью 750 долларов может выполнять в четыре раза больше вычислений одновременно. В сочетании с « атакой дня рождения » это может привести к серьезным уязвимостям безопасности.

По состоянию на 23 июля 2024 г. (через 8 месяцев после выпуска PHP 8.3) W3Techs сообщает, что 77,4% веб-сайтов, использующих PHP, используют версии 8.0 или старше (которые больше не поддерживаются командой разработчиков PHP). PHP версии 5 по-прежнему используется на 14,3% всех веб-сайтов.

Zend предлагает платную активную долгосрочную поддержку PHP (PHP LTS), которая включает исправления безопасности:

• опционально платно за поддерживаемые версии PHP;
• платится только за устаревшие ветки PHP, включая:
  • 8.0 до конца 2025 года;
  • 7.4, 7.3 и 7.2 до конца 2026 года.

Срок платной поддержки каждой ветки, начиная с выпуска исходной стабильной версии, составляет не менее 5 лет.

■ 8.3 ■ 8.2
■ 8.1
22.62%
Поддерживаемые версии PHP

■ 8.0
■ 7.4 ■ 7.3 ■ 7.2
58.75%
Неподдерживаемые ветки (доступен PHP LTS)

■ 7.1 ■ 7.0
■ 5.x ■ 4.x
18.70%
Неподдерживаемые ветки

См. также

• Сравнение языков программирования
• Список пакетов Apache – MySQL – PHP
• Список ускорителей PHP
• Список редакторов PHP
• PEAR (репозиторий расширений и приложений PHP)
• PHP-ускоритель
• Процессор шаблонов
• XAMPP (бесплатный пакет кроссплатформенных веб-серверных решений с открытым исходным кодом)
• Zend-сервер

Дальнейшее чтение

• Форд, Пол (11 июня 2015 г.). «Что такое код?» . Блумберг Бизнесуик . Какой абсолютный минимум я должен знать о PHP?

Внешние ссылки

• Официальный сайт
• PHP в Керли