Language Reference

• Basic syntax
  • PHP tags
  • Escaping from HTML
  • Instruction separation
  • Comments
• Types
  • Introduction
  • Booleans
  • Integers
  • Floating point numbers
  • Strings
  • Arrays
  • Iterables
  • Objects
  • Resources
  • NULL
  • Callbacks / Callables
  • Pseudo-types and variables used in this documentation
  • Type Juggling
• Variables
  • Basics
  • Predefined Variables
  • Variable scope
  • Variable variables
  • Variables From External Sources
• Constants
  • Syntax
  • Magic constants
• Expressions
• Operators
  • Operator Precedence
  • Arithmetic Operators
  • Assignment Operators
  • Bitwise Operators
  • Comparison Operators
  • Error Control Operators
  • Execution Operators
  • Incrementing/Decrementing Operators
  • Logical Operators
  • String Operators
  • Array Operators
  • Type Operators
• Control Structures
  • Introduction
  • if
  • else
  • elseif/else if
  • Alternative syntax for control structures
  • while
  • do-while
  • for
  • foreach
  • break
  • continue
  • switch
  • declare
  • return
  • require
  • include
  • require_once
  • include_once
  • goto
• Functions
  • User-defined functions
  • Function arguments
  • Returning values
  • Variable functions
  • Internal (built-in) functions
  • Anonymous functions
• Classes and Objects
  • Introduction
  • The Basics
  • Properties
  • Class Constants
  • Autoloading Classes
  • Constructors and Destructors
  • Visibility
  • Object Inheritance
  • Scope Resolution Operator (::)
  • Static Keyword
  • Class Abstraction
  • Object Interfaces
  • Traits
  • Anonymous classes
  • Overloading
  • Object Iteration
  • Magic Methods
  • Final Keyword
  • Object Cloning
  • Comparing Objects
  • Type Hinting
  • Late Static Bindings
  • Objects and references
  • Object Serialization
  • Covariance and Contravariance
  • OOP Changelog
• Namespaces
  • Namespaces overview
  • Defining namespaces
  • Declaring sub-namespaces
  • Defining multiple namespaces in the same file
  • Using namespaces: Basics
  • Namespaces and dynamic language features
  • namespace keyword and __NAMESPACE__ constant
  • Using namespaces: Aliasing/Importing
  • Global space
  • Using namespaces: fallback to global function/constant
  • Name resolution rules
  • FAQ: things you need to know about namespaces
• Errors
  • Basics
  • Errors in PHP 7
• Exceptions
  • Extending Exceptions
• Generators
  • Generators overview
  • Generator syntax
  • Comparing generators with Iterator objects
• References Explained
  • What References Are
  • What References Do
  • What References Are Not
  • Passing by Reference
  • Returning References
  • Unsetting References
  • Spotting References
• Predefined Variables
  • Superglobals — Superglobals are built-in variables that are always available in all scopes
  • $GLOBALS — References all variables available in global scope
  • $_SERVER — Server and execution environment information
  • $_GET — HTTP GET variables
  • $_POST — HTTP POST variables
  • $_FILES — HTTP File Upload variables
  • $_REQUEST — HTTP Request variables
  • $_SESSION — Session variables
  • $_ENV — Environment variables
  • $_COOKIE — HTTP Cookies
  • $php_errormsg — The previous error message
  • $HTTP_RAW_POST_DATA — Raw POST data
  • $http_response_header — HTTP response headers
  • $argc — The number of arguments passed to script
  • $argv — Array of arguments passed to script
• Predefined Exceptions
  • Exception
  • ErrorException
  • Error
  • ArgumentCountError
  • ArithmeticError
  • AssertionError
  • DivisionByZeroError
  • CompileError
  • ParseError
  • TypeError
• Predefined Interfaces and Classes
  • Traversable — The Traversable interface
  • Iterator — The Iterator interface
  • IteratorAggregate — The IteratorAggregate interface
  • Throwable
  • ArrayAccess — The ArrayAccess interface
  • Serializable — The Serializable interface
  • Closure — The Closure class
  • Generator — The Generator class
  • WeakReference — The WeakReference class
• Context options and parameters
  • Socket context options — Socket context option listing
  • HTTP context options — HTTP context option listing
  • FTP context options — FTP context option listing
  • SSL context options — SSL context option listing
  • CURL context options — CURL context option listing
  • Phar context options — Phar context option listing
  • MongoDB context options — MongoDB context option listing
  • Context parameters — Context parameter listing
  • Zip context options — Zip context option listing
• Supported Protocols and Wrappers
  • file:// — Accessing local filesystem
  • http:// — Accessing HTTP(s) URLs
  • ftp:// — Accessing FTP(s) URLs
  • php:// — Accessing various I/O streams
  • zlib:// — Compression Streams
  • data:// — Data (RFC 2397)
  • glob:// — Find pathnames matching pattern
  • phar:// — PHP Archive
  • ssh2:// — Secure Shell 2
  • rar:// — RAR
  • ogg:// — Audio streams
  • expect:// — Process Interaction Streams