Diese Konstanten werden vom PHP-Core definiert. Das beinhaltet PHP, die Zend-Engine- und SAPI-Module.
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 von ZEND_THREAD_SAFE
   PHP_DEBUG
    (bool)
    Alias von 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' oder 'Unknown' (unbekannt).
     Verfügbar ab 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.
     Verfügbar ab PHP 7.2.0.
    
   PHP_FLOAT_MIN
    (float)
   - PHP_FLOAT_MAX zu
     verwenden. Verfügbar ab 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 (oder
     PHP_PREFIX . "\\ext" unter 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).
     Nur unter der CLI-SAPI verfügbar.
    
   STDIN
    (resource)
   stdin).
     Nur unter der CLI-SAPI verfügbar.
    
   STDOUT
    (resource)
   stdout).
     Nur unter der CLI-SAPI verfügbar.
    
   Siehe auch: Magische Konstanten.
Alle Konstanten der Kern-Extensions sind in PHP automatisch definiert.