Predefined Classes
List of Resource Types
List of Reserved Words
PHP Manual

## Predefined Constants

### Core Predefined Constants

These constants are defined by the PHP core. This includes PHP, the Zend engine, and SAPI modules.

`PHP_VERSION` (string)
  The current PHP version as a string in "major.minor.release[extra]" notation.
`PHP_MAJOR_VERSION` (integer)
  The current PHP "major" version as an integer (e.g., int(5) from version "5.2.7-extra"). Available since PHP 5.2.7.
`PHP_MINOR_VERSION` (integer)
  The current PHP "minor" version as an integer (e.g., int(2) from version "5.2.7-extra"). Available since PHP 5.2.7.
`PHP_RELEASE_VERSION` (integer)
  The current PHP "release" version as an integer (e.g., int(7) from version "5.2.7-extra"). Available since PHP 5.2.7.
`PHP_VERSION_ID` (integer)
  The current PHP version as an integer, useful for version comparisons (e.g., int(50207) from version "5.2.7-extra"). Available since PHP 5.2.7.
`PHP_EXTRA_VERSION` (string)
  The current PHP "extra" version as a string (e.g., '-extra' from version "5.2.7-extra"). Often used by distribution vendors to indicate a package version. Available since PHP 5.2.7.
`PHP_ZTS` (integer)
  Available since PHP 5.2.7.
`PHP_DEBUG` (integer)
  Available since PHP 5.2.7.
`PHP_MAXPATHLEN` (integer)
  The maximum length of filenames (including path) supported by this build of PHP. Available since PHP 5.3.0.
`PHP_OS` (string)
`PHP_SAPI` (string)
  The Server API for this build of PHP. Available since PHP 4.2.0. See also php_sapi_name().
`PHP_EOL` (string)
  The correct 'End Of Line' symbol for this platform. Available since PHP 4.3.10 and PHP 5.0.2
`PHP_INT_MAX` (integer)
  The largest integer supported in this build of PHP. Usually int(2147483647). Available since PHP 4.4.0 and PHP 5.0.5
`PHP_INT_SIZE` (integer)
  Available since PHP 4.4.0 and PHP 5.0.5
`DEFAULT_INCLUDE_PATH` (string)
`PEAR_INSTALL_DIR` (string)
`PEAR_EXTENSION_DIR` (string)
`PHP_EXTENSION_DIR` (string)
`PHP_PREFIX` (string)
  The value "--prefix" was set to at configure. Available since PHP 4.3.0.
`PHP_BINDIR` (string)
  Specifies where the binaries were installed into.
`PHP_BINARY` (string)
  Specifies the PHP binary path during script execution. Available since PHP 5.4.
`PHP_MANDIR` (string)
  Specifies where the manpages were installed into. Available since PHP 5.3.7.
`PHP_LIBDIR` (string)
`PHP_DATADIR` (string)
`PHP_SYSCONFDIR` (string)
`PHP_LOCALSTATEDIR` (string)
`PHP_CONFIG_FILE_PATH` (string)
`PHP_CONFIG_FILE_SCAN_DIR` (string)
`PHP_SHLIB_SUFFIX` (string)
  The build-platform's shared library suffix, such as "so" (most Unixes) or "dll" (Windows). Available since PHP 4.3.0
`E_ERROR` (integer)
  Error reporting constant
`E_WARNING` (integer)
`E_PARSE` (integer)
`E_NOTICE` (integer)
`E_CORE_ERROR` (integer)
`E_CORE_WARNING` (integer)
`E_COMPILE_ERROR` (integer)
`E_COMPILE_WARNING` (integer)
`E_USER_ERROR` (integer)
`E_USER_WARNING` (integer)
`E_USER_NOTICE` (integer)
`E_DEPRECATED` (integer)
  Available since PHP 5.3.0
`E_USER_DEPRECATED` (integer)
  Available since PHP 5.3.0
`E_ALL` (integer)
`E_STRICT` (integer)
  Available since PHP 5.0.0
`__COMPILER_HALT_OFFSET__` (integer)
  Available since PHP 5.1.0
`TRUE` (boolean)
  See Booleans.
`FALSE` (boolean)
  See Booleans.
`NULL` (boolean)
  See Null.

See also: Magic constants.

### Standard Predefined Constants

All constants from core extensions are defined in PHP by default.

Predefined Classes
List of Resource Types
List of Reserved Words
PHP Manual