PHP Magic Constants

Posted 2024-05-17 07:40:16

PHP Predefined Constants

PHP has nine predefined constants that change value depending on where they are used, and therefor they are called "magic constants".

These magic constants are written with a double underscore at the start and the end, except for the ClassName::class constant.

Here are the magic constants, with descriptions and examples:

Constant	Description
__CLASS__	If used inside a class, the class name is returned.	Try it »
__DIR__	The directory of the file.	Try it »
__FILE__	The file name including the full path.	Try it »
__FUNCTION__	If inside a function, the function name is returned.	Try it »
__LINE__	The current line number.	Try it »
__METHOD__	If used inside a function that belongs to a class, both class and function name is returned.	Try it »
__NAMESPACE__	If used inside a namespace, the name of the namespace is returned.	Try it »
__TRAIT__	If used inside a trait, the trait name is returned.	Try it »
ClassName::class	Returns the name of the specified class and the name of the namespace, if any.	Try it »

Note:

The magic constants are case-insensitive, meaning __LINE__ returns the same as __line__.

Please log in to like, share and comment!

Superglobals were introduced in PHP 4.1.0, and are built-in variables that are always available...

By 2024-05-17 08:08:10 0 4K

PHP Math

PHP has a set of math functions that allows you to perform mathematical tasks on numbers. PHP...

By 2024-05-17 07:39:09 0 3K

Multi-line Comments Multi-line comments start with /* and end with */. Any text...

By 2024-05-17 07:15:48 0 3K

PHP Indexed Arrays In indexed arrays each item has an index number. By default, the first item...

By 2024-05-17 08:00:38 0 2K

Slicing You can return a range of characters by using the substr() function. Specify...

By 2024-05-17 07:31:23 1 3K