These words have a special meaning in PHP. Some of them are like functions, some like constants ... But they are not, they are only part of the language structure. You cannot use any of them as constants, method names, or class names. However, they can be used as variable names, but this leads to confusion.
PHP Keywords
And or XOR __file__ exception (PHP 5)
__line__ Array () as Break case
Class Const Continue declare default
Die () do echo Else ElseIf
Empty () Enddeclare endfor Endforeach endif
Endswitch endwhile eval () exit () extends
For foreach function Global if
Include include_once isset () list () new
Print require require_once return static
Switch unset () use Var while
__function__ __class__ __method__ Final (PHP 5) php_user_filter (PHP 5)
Interface (PHP 5) implements (PHP 5) extends Public (PHP 5) Private (PHP 5)
Protected (PHP 5) abstract (PHP 5) Clone (PHP 5) Try (PHP 5) catch (PHP 5)
Throw (PHP 5) cfunction (PHP 4 only) This (PHP 5 only)
pre-defined classes
section lists the standard predefined classes. Various extension libraries define other classes, which are described in their respective reference documents.
Standard class
These classes are defined by a number of standard functions built into PHP.
Directory
Created by Dir ().
StdClass
__php_incomplete_class
Pre-defined classes from PHP 5
These additional predefined classes are introduced by PHP 5.0.0.
exception
Php_user_filter
Closure
A pre-defined final class closure is introduced in PHP5.3.0, which can be used to implement anonymous functions
The class's construction method prohibits manually creating objects of that class (which results in a e_recoverable_error error). The class also has a __invoke method to make magic calls.
Special classes
The following tokens cannot be used as class names because they have a special purpose.
Self
Parent
pre-defined constants
Kernel pre-defined constants
These constants are defined in the kernel of PHP. It contains PHP, Zend engines, and SAPI modules.
Php_version (String)
Php_os (String)
Php_sapi (String)
Available from PHP 4.2.0. See Php_sapi_name ().
Php_eol (String)
Available from PHP 4.3.10 and PHP 5.0.2
Php_int_max (integer)
Available from PHP 4.4.0 and PHP 5.0.5
Php_int_size (integer)
Available from 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)
Available from PHP 4.3.0
Php_bindir (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)
Available from PHP 4.3.0
Php_output_handler_start (integer)
Php_output_handler_cont (integer)
Php_output_handler_end (integer)
E_error (integer)
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_all (integer)
E_strict (integer)
Valid from PHP 5.0.0
__compiler_halt_offset__ (integer)
Valid from PHP 5.1.0
See also Magic constants.
Standard pre-defined constants
These constants are defined by default in PHP.
Extr_overwrite (integer)
Extr_skip (integer)
Extr_prefix_same (integer)
Extr_prefix_all (integer)
Extr_prefix_invalid (integer)
Extr_prefix_if_exists (integer)
Extr_if_exists (integer)
SORT_ASC (integer)
Sort_desc (integer)
Sort_regular (integer)
Sort_numeric (integer)
Sort_string (integer)
Case_lower (integer)
Case_upper (integer)
Count_normal (integer)
Count_recursive (integer)
Assert_active (integer)
Assert_callback (integer)
Assert_bail (integer)
Assert_warning (integer)
Assert_quiet_eval (integer)
Connection_aborted (integer)
Connection_normal (integer)
Connection_timeout (integer)
Ini_user (integer)
Ini_perdir (integer)
Ini_system (integer)
Ini_all (integer)
M_e (float)
M_LOG2E (float)
m_log10e (float)
M_LN2 (float)
M_ln10 (float)
M_PI (float)
M_pi_2 (float)
M_pi_4 (float)
M_1_PI (float)
M_2_PI (float)
M_2_SQRTPI (float)
M_sqrt2 (float)
M_sqrt1_2 (float)
Crypt_salt_length (integer)
Crypt_std_des (integer)
Crypt_ext_des (integer)
CRYPT_MD5 (integer)
Crypt_blowfish (integer)
Directory_separator (String)
Seek_set (integer)
Seek_cur (integer)
Seek_end (integer)
Lock_sh (integer)
LOCK_EX (integer)
Lock_un (integer)
LOCK_NB (integer)
Html_specialchars (integer)
Html_entities (integer)
Ent_compat (integer)
Ent_quotes (integer)
Ent_noquotes (integer)
Info_general (integer)
Info_credits (integer)
Info_configuration (integer)
Info_modules (integer)
Info_environment (integer)
Info_variables (integer)
Info_license (integer)
Info_all (integer)
Credits_group (integer)
Credits_general (integer)
Credits_sapi (integer)
Credits_modules (integer)
Credits_docs (integer)
Credits_fullpage (integer)
Credits_qa (integer)
Credits_all (integer)
Str_pad_left (integer)
Str_pad_right (integer)
Str_pad_both (integer)
Pathinfo_dirname (integer)
Pathinfo_basename (integer)
Pathinfo_extension (integer)
Path_separator (String)
Char_max (integer)
Lc_ctype (integer)
Lc_numeric (integer)
Lc_time (integer)
Lc_collate (integer)
Lc_monetary (integer)
Lc_all (integer)
Lc_messages (integer)
Abday_1 (integer)
Abday_2 (integer)
Abday_3 (integer)
Abday_4 (integer)
Abday_5 (integer)
Abday_6 (integer)
Abday_7 (integer)
Day_1 (integer)
Day_2 (integer)
Day_3 (integer)
Day_4 (integer)
Day_5 (integer)
Day_6 (integer)
Day_7 (integer)
Abmon_1 (integer)
Abmon_2 (integer)
Abmon_3 (integer)
Abmon_4 (integer)
Abmon_5 (integer)
Abmon_6 (integer)
Abmon_7 (integer)
Abmon_8 (integer)
Abmon_9 (integer)
Abmon_10 (integer)
Abmon_11 (integer)
Abmon_12 (integer)
Mon_1 (integer)
Mon_2 (integer)
Mon_3 (integer)
Mon_4 (integer)
Mon_5 (integer)
Mon_6 (integer)
Mon_7 (integer)
Mon_8 (integer)
Mon_9 (integer)
Mon_10 (integer)
Mon_11 (integer)
Mon_12 (integer)
Am_str (integer)
Pm_str (integer)
D_T_FMT (integer)
D_FMT (integer)
T_FMT (integer)
T_FMT_AMPM (integer)
ERA (integer)
Era_year (integer)
ERA_D_T_FMT (integer)
ERA_D_FMT (integer)
ERA_T_FMT (integer)
Alt_digits (integer)
Int_curr_symbol (integer)
Currency_symbol (integer)
Crncystr (integer)
Mon_decimal_point (integer)
Mon_thousands_sep (integer)
Mon_grouping (integer)
Positive_sign (integer)
Negative_sign (integer)
Int_frac_digits (integer)
Frac_digits (integer)
P_cs_precedes (integer)
P_sep_by_space (integer)
N_cs_precedes (integer)
N_sep_by_space (integer)
P_sign_posn (integer)
N_sign_posn (integer)
Decimal_point (integer)
Radixchar (integer)
Thousands_sep (integer)
Thousep (integer)
GROUPING (integer)
yesexpr (integer)
noexpr (integer)
Yesstr (integer)
Nostr (integer)
CodeSet (integer)
Log_emerg (integer)
Log_alert (integer)
Log_crit (integer)
Log_err (integer)
Log_warning (integer)
Log_notice (integer)
Log_info (integer)
Log_debug (integer)
Log_kern (integer)
Log_user (integer)
Log_mail (integer)
Log_daemon (integer)
Log_auth (integer)
Log_syslog (integer)
LOG_LPR (integer)
Log_news (integer)
LOG_UUCP (integer)
Log_cron (integer)
Log_authpriv (integer)
Log_local0 (integer)
Log_local1 (integer)
Log_local2 (integer)
Log_local3 (integer)
Log_local4 (integer)
LOG_LOCAL5 (integer)
LOG_LOCAL6 (integer)
LOG_LOCAL7 (integer)
Log_pid (integer)
Log_cons (integer)
Log_odelay (integer)
Log_ndelay (integer)
Log_nowait (integer)
Log_perror (integer)
http://www.bkjia.com/PHPjc/326091.html www.bkjia.com true http://www.bkjia.com/PHPjc/326091.html techarticle these words have a special meaning in PHP. Some of them are like functions, some like constants ... But they are not, they are only part of the language structure. Cannot use their ...
