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
(int)
The current PHP "major" version as an integer (e.g., int(5)
from version "5.2.7-extra").
PHP_MINOR_VERSION
(int)
The current PHP "minor" version as an integer (e.g., int(2)
from version "5.2.7-extra").
PHP_RELEASE_VERSION
(int)
The current PHP "release" version as an integer (e.g., int(7)
from version "5.2.7-extra").
PHP_VERSION_ID
(int)
The current PHP version as an integer, useful for
version comparisons (e.g., int(50207) from version "5.2.7-extra").
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.
PHP_ZTS
(int)
PHP_DEBUG
(int)
PHP_MAXPATHLEN
(int)
The maximum length of filenames (including path) supported
by this build of PHP.
PHP_OS
(string)
The operating system PHP was built for.
PHP_OS_FAMILY
(string)
The operating system family PHP was built for. One of
'Windows', 'BSD',
'Darwin', 'Solaris',
'Linux' or 'Unknown'.
Available as of PHP 7.2.0.
PHP_SAPI
(string)
The Server API for this build of PHP.
See also php_sapi_name.
PHP_EOL
(string)
The correct 'End Of Line' symbol for this platform.
PHP_INT_MAX
(int)
The largest integer supported in this build of PHP. Usually int(2147483647)
in 32 bit systems and int(9223372036854775807) in 64 bit systems.
PHP_INT_MIN
(int)
The smallest integer supported in this build of PHP. Usually int(-2147483648) in 32 bit systems and
int(-9223372036854775808) in 64 bit systems.
Usually, PHP_INT_MIN === ~PHP_INT_MAX.
PHP_INT_SIZE
(int)
The size of an integer in bytes in this build of PHP.
PHP_FLOAT_DIG
(int)
Number of decimal digits that can be rounded into a float and back
without precision loss.
Available as of PHP 7.2.0.
PHP_FLOAT_EPSILON
(float)
Smallest representable positive number x, so that x + 1.0 !=
1.0.
Available as of PHP 7.2.0.
PHP_FLOAT_MIN
(float)
Smallest representable positive floating point number.
If you need the smallest representable negative floating point number, use - PHP_FLOAT_MAX.
Available as of PHP 7.2.0.
PHP_FLOAT_MAX
(float)
Largest representable floating point number.
Available as of PHP 7.2.0.
DEFAULT_INCLUDE_PATH
(string)
PEAR_INSTALL_DIR
(string)
PEAR_EXTENSION_DIR
(string)
PHP_EXTENSION_DIR
(string)
The default directory where to look for dynamically loadable extensions
(unless overridden by extension_dir).
Defaults to PHP_PREFIX (or PHP_PREFIX . "\\ext" on Windows).
PHP_PREFIX
(string)
The value was set to at configure.
On Windows, it is the value
was set to at configure.
PHP_BINDIR
(string)
The value was set to at configure.
On Windows, it is the value
was set to at configure.
PHP_BINARY
(string)
Specifies the PHP binary path during script execution.
PHP_MANDIR
(string)
Specifies where the manpages were installed into.
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).
PHP_FD_SETSIZE
(string)
The maximum number of file descriptors for select system calls. Available
as of PHP 7.1.0.
E_ERROR
(int)
Error reporting constant
E_WARNING
(int)
Error reporting constant
E_PARSE
(int)
Error reporting constant
E_NOTICE
(int)
Error reporting constant
E_CORE_ERROR
(int)
Error reporting constant
E_CORE_WARNING
(int)
Error reporting constant
E_COMPILE_ERROR
(int)
Error reporting constant
E_COMPILE_WARNING
(int)
Error reporting constant
E_USER_ERROR
(int)
Error reporting constant
E_USER_WARNING
(int)
Error reporting constant
E_USER_NOTICE
(int)
Error reporting constant
E_RECOVERABLE_ERROR
(int)
Error reporting constant.
E_DEPRECATED
(int)
Error reporting constant.
E_USER_DEPRECATED
(int)
Error reporting constant.
E_ALL
(int)
Error reporting constant
E_STRICT
(int)
Error reporting constant
__COMPILER_HALT_OFFSET__
(int)
&true;
(bool)
See Booleans.
&false;
(bool)
See Booleans.
&null;
(null)
See Null.
PHP_WINDOWS_EVENT_CTRL_C
(int)
A Windows CTRL+C event.
Available as of PHP 7.4.0 (Windows only).
PHP_WINDOWS_EVENT_CTRL_BREAK
(int)
A Windows CTRL+BREAK event.
Available as of PHP 7.4.0 (Windows only).
See also: Magic
constants.