Learn about 8 magic constants in PHP

This article will let you know about the 8 magic constants in PHP. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

Most of the constants in PHP are unchanged, but there are 8 constants that will change as the position of the code where they are located changes. These 8 constants are called is a magic constant.

__LINE__

The current line number in the file

__FILE__

The full path to the file and the file name. If used in an included file, returns the included file name.

__DIR__

The directory where the file is located. If used within an included file, returns the directory where the included file is located. It is equivalent to dirname(__FILE__). Directory names do not include the trailing slash unless they are the root directory.

__FUNCTION__

Function name, case-sensitive.

__CLASS__

The name of the class is case-sensitive. The class name includes the scope in which it is declared (e.g. Foo\Bar). Note that since PHP 5.4 __CLASS__ also works for traits. When used within a trait method, __CLASS__ is the name of the class that calls the trait method. You can use get_class to replace the name of __CLASS__

__TRAIT__

Trait, which is case-sensitive. Including the scope in which it is declared (e.g. Foo\Bar).

__METHOD__

The method name of the class is case-sensitive. When used in a class, the class name will be output, such as: trick::doitagain

__NAMESPACE__

The name of the current namespace, case-sensitive. This constant is defined at compile time.

Definition such as: namespace Api\Controller;

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