WS WhereIsStuff
Tutorial Guides
Log In
Sign Up

Advertisement

Google Ad Slot: content-top

PHP Magic Constants

~1 min read · PHP
On this page
❮ Previous Next ❯

Magic constants are predefined constants that change based on their location in the code. Unlike regular constants, they do not have fixed values; instead, their values change depending on where they are used. Magic constants start and end with double underscores (__), except for the ClassName::class constant.


Summary of PHP Magic Constants

Magic Constant

Description

__LINE__

Current line number

__FILE__

Full path and filename of the file

__DIR__

Directory of the file

__FUNCTION__

Function name

__METHOD__

Class method name

__NAMESPACE__

Current namespace

__TRAIT__

Trait name (PHP 5.4+)

ClassName::class

Returns the name of the specified class and the name of the namespace, if any.

1. __LINE__


  • Represents the current line number in the script.
Example
Try it yourself

2. __FILE__


  • Represents the full path and filename of the file.
  • Useful for finding the script's exact location.
Example
Try it yourself

3. __DIR__


  • Represents the directory of the file.
Example
Try it yourself

4. __FUNCTION__


  • Represents the function name (case-sensitive) where it is used.
  • If used outside a function, it will return an empty string.
Example
Try it yourself

5. __CLASS__


  • Represents the class name (case-sensitive) where it is used.
  • If used outside a class, it returns an empty string.
  • From PHP 5.4 onward, __CLASS__ includes the namespace in its value (if applicable).
Example
getClassName(); ?>
Try it yourself

6. __METHOD__


  • Represents the class method name where it is used.
  • Combines the class name and the method name.
Example
myMethod(); ?>
Try it yourself

7. __NAMESPACE__


  • Represents the name of the current namespace.
  • If used outside of any namespace, it returns an empty string.
Example
Try it yourself

8. __TRAIT__ (Introduced in PHP 5.4)


  • Represents the trait name where it is used.
  • Useful for traits to refer to themselves.
Example
getTraitName(); ?>
Try it yourself

9. ClassName::class


  • Returns the name of the specified class and the name of the namespace, if any.
Example
myValue(); ?>
Try it yourself

❮ Previous Next ❯