__File__
This default constant is a PHP program file name. If the reference file (include or Require) is referenced to the file name in the reference file, not the file name of the reference.
__Line__ This default constant is the number of lines of PHP. If the reference file (include or Require), the constant within the reference file is the row of the reference file, not the file line referenced.
PHP_VERSION This creation constant is the version of the PHP program, such as '3.0.8-dev'.
PHP_OS This built-in constant refers to the operating system name of the PHP parser, such as 'Linux'.
True This constant is true (TRUE).
False This constant is a pseudo value.
E_ERROR This constant refers to a nearest error.
E_WARNING This constant refers to the nearest warning.
E_PARSE Benography is a potential problem for analyzing syntax.
E_NOTICE This could not occur unusual but not necessarily an error. For example, access a variable that does not exist.
These E_ begin a constant, you can refer to the Error_Reporting () function, there is more related instructions.
Of course, when the program is written, the default constant above is not enough. The functionality of define () allows us to define the constant required. See the following example
Define ("Copyright", "Copyright? 2000, Netleader.126.com"); Echo Copyright;?>>
