自 PHP 5 起引进了新常量 E_STRICT，其值为 2048。它提供了对用户代码的协同性和向前兼容性的运行时 PHP 建议，有助于使用户保持最新和最好的编程风格。例如在使用已过时的函数时 STRICT 信息会提出警告。
Note: E_ALL 不包括 E_STRICT，因此其默认未激活。
matthew dot flaschen at gatech dot edu (2013-06-20 09:52:23)
E_ALL includes E_STRICT in 5.4.0 and up.
Anonymous (2012-08-13 13:28:09)
According to the notes in the php.ini file, E_ALL *does* include E_STRICT; to exclude it you would use E_ALL & ~E_STRICT
This may be useful for someone who has upgraded and kept their old php.ini
Anonymous (2008-03-31 05:52:44)
To enable full error reporting (recommended for development boxes) use:
use error_reporting(E_ALL | E_STRICT);
or in php.ini:
error_reporting = E_ALL | E_STRICT