PHP Basics - PHP magic constants

PHP contain 9 A magic constant . Their values change as their position in the code changes .

name	explain
__LINE__	The current line number in the file .
__FILE__	The full path and filename of the file . If used in the included file , Then return the included file name .
__DIR__	Directory of files . If used in included files , Returns the directory where the included files are located . It is equivalent to dirname(__FILE__). Unless it's the root directory , Otherwise, the name in the directory does not include the trailing slash .
__NAMESPACE__	The name of the current namespace .
__TRAIT__	Trait Name .Trait The name includes the scope it is declared （ for example Foo\Bar）.
__CLASS__	The name of the current class . The class name includes its declared scope （ for example Foo\Bar）. When used in trait In the method ,CLASS Is to call trait The name of the class of the method .
__FUNCTION__	The name of the current function . Anonymous functions are {closure}.
__METHOD__	Class .
ClassName::class	Full class name .