These constants are defined by the PHP core. This includes PHP, the Zend engine, and SAPI modules.
PHP_VERSION
(string)
PHP_MAJOR_VERSION
(int)
PHP_MINOR_VERSION
(int)
PHP_RELEASE_VERSION
(int)
PHP_VERSION_ID
(int)
PHP_EXTRA_VERSION
(string)
ZEND_THREAD_SAFE
(bool)
ZEND_DEBUG_BUILD
(bool)
PHP_ZTS
(bool)
Alias of ZEND_THREAD_SAFE
PHP_DEBUG
(bool)
Alias of ZEND_DEBUG_BUILD
DEBUG_BACKTRACE_PROVIDE_OBJECT
(int)
DEBUG_BACKTRACE_IGNORE_ARGS
(int)
PHP_MAXPATHLEN
(int)
PHP_OS
(string)
PHP_OS_FAMILY
(string)
'Windows', 'BSD',
'Darwin', 'Solaris',
'Linux' or 'Unknown'.
Available as of PHP 7.2.0.
PHP_SAPI
(string)
PHP_EOL
(string)
PHP_INT_MAX
(int)
PHP_INT_MIN
(int)
PHP_INT_SIZE
(int)
PHP_FLOAT_DIG
(int)
PHP_FLOAT_EPSILON
(float)
x + 1.0 !=
1.0.
Available as of PHP 7.2.0.
PHP_FLOAT_MIN
(float)
- PHP_FLOAT_MAX.
Available as of PHP 7.2.0.
PHP_FLOAT_MAX
(float)
DEFAULT_INCLUDE_PATH
(string)
PEAR_INSTALL_DIR
(string)
PEAR_EXTENSION_DIR
(string)
PHP_EXTENSION_DIR
(string)
PHP_PREFIX (or PHP_PREFIX . "\\ext" on Windows).
PHP_PREFIX
(string)
PHP_BINDIR
(string)
PHP_SBINDIR
(string)
PHP_BINARY
(string)
PHP_MANDIR
(string)
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)
PHP_FD_SETSIZE
(int)
E_ERROR
(int)
E_WARNING
(int)
E_PARSE
(int)
E_NOTICE
(int)
E_CORE_ERROR
(int)
E_CORE_WARNING
(int)
E_COMPILE_ERROR
(int)
E_COMPILE_WARNING
(int)
E_USER_ERROR
(int)
E_USER_WARNING
(int)
E_USER_NOTICE
(int)
E_RECOVERABLE_ERROR
(int)
E_DEPRECATED
(int)
E_USER_DEPRECATED
(int)
E_ALL
(int)
E_STRICT
(int)
__COMPILER_HALT_OFFSET__
(int)
true
(bool)
false
(bool)
null
(null)
PHP_WINDOWS_EVENT_CTRL_C
(int)
PHP_WINDOWS_EVENT_CTRL_BREAK
(int)
PHP_CLI_PROCESS_TITLE
(bool)
STDERR
(resource)
stderr.
Available only under the CLI SAPI.
STDIN
(resource)
stdin.
Available only under the CLI SAPI.
STDOUT
(resource)
stdout.
Available only under the CLI SAPI.
See also: Magic constants.
All constants from core extensions are defined in PHP by default.