PHP: Hypertext Preprocessor

关键词列表

这些词语在 PHP 中有着特殊的意义。它们中有些像是函数，有些像是常量，但是它们不是真的，它们只是语言结构的一部分。不能使用它们的任何一个作为常量、类名或函数名。但是它们可以被用作类的属性、常量以及类的方法名，或者接口名和 traits 名，除了 class 不能被用作常量名。

**PHP 关键词**
__halt_compiler()	abstract	and	array()	as
break	callable	case	catch	class
clone	const	continue	declare	default
die()	do	echo	else	elseif
empty()	enddeclare	endfor	endforeach	endif
endswitch	endwhile	eval()	exit()	extends
final	finally	fn（从 PHP 7.4 开始）	for	`foreach`
function	global	goto	if	implements
include	include_once	instanceof	insteadof	interface
isset()	list()	match（从 PHP 8.0 开始）	namespace	new
or	print	private	protected	public
readonly（自 PHP 8.1.0 起）*	require	require_once	return	static
switch	throw	trait	try	unset()
use	var	while	xor	yield
yield from

* readonly 可用作函数名。

**编译时常量**
__CLASS__	__DIR__	__FILE__	__FUNCTION__	__LINE__	__METHOD__
__NAMESPACE__	__TRAIT__

发现了问题？

了解如何改进此页面 • 提交拉取请求 • 报告一个错误

＋添加备注

用户贡献的备注 4 notes

down

martindilling at gmail dot com ¶

11 years ago

RegEx to find all the keywords:

\b(
(a(bstract|nd|rray|s))|
(c(a(llable|se|tch)|l(ass|one)|on(st|tinue)))|
(d(e(clare|fault)|ie|o))|
(e(cho|lse(if)?|mpty|nd(declare|for(each)?|if|switch|while)|val|x(it|tends)))|
(f(inal|or(each)?|unction))|
(g(lobal|oto))|
(i(f|mplements|n(clude(_once)?|st(anceof|eadof)|terface)|sset))|
(n(amespace|ew))|
(p(r(i(nt|vate)|otected)|ublic))|
(re(quire(_once)?|turn))|
(s(tatic|witch))|
(t(hrow|r(ait|y)))|
(u(nset|se))|
(__halt_compiler|break|list|(x)?or|var|while)
)\b

down

Thomas Hansen ¶

8 years ago

Please note that reserved words are still not allowed to be used as namespace or as part of it:

<?php
namespace MyNameSpace\List;

class Test
{
}
?>

This will fail with a Parse error:  syntax error, unexpected 'List' (T_LIST), expecting identifier (T_STRING)

down

Chris ¶

12 years ago

Here they are as arrays:

<?php
$keywords = array('__halt_compiler', 'abstract', 'and', 'array', 'as', 'break', 'callable', 'case', 'catch', 'class', 'clone', 'const', 'continue', 'declare', 'default', 'die', 'do', 'echo', 'else', 'elseif', 'empty', 'enddeclare', 'endfor', 'endforeach', 'endif', 'endswitch', 'endwhile', 'eval', 'exit', 'extends', 'final', 'for', 'foreach', 'function', 'global', 'goto', 'if', 'implements', 'include', 'include_once', 'instanceof', 'insteadof', 'interface', 'isset', 'list', 'namespace', 'new', 'or', 'print', 'private', 'protected', 'public', 'require', 'require_once', 'return', 'static', 'switch', 'throw', 'trait', 'try', 'unset', 'use', 'var', 'while', 'xor');

$predefined_constants = array('__CLASS__', '__DIR__', '__FILE__', '__FUNCTION__', '__LINE__', '__METHOD__', '__NAMESPACE__', '__TRAIT__');
?>

Along with get_defined_functions() and get_defined_constants(), this can be useful for checking eval() statements.

down

-1

Chocopie ¶

8 months ago

From php8, reserved keywords such as `Interface` or `Trait` can be used as part of the namespace.

<?php
namespace App\Entity\Interface;

interface FooInterface
{

}

https://wiki.php.net/rfc/namespaced_names_as_token