PHP TutorialLesson 14Free preview

PHP Magic Constants

This lesson is part of PHP · All levels

Summary

Magic constants are special constants whose values are automatically determined by PHP according to where they are written. The characteristic is that it is always preceded and terminated by two double bottom lines, for example __FILE__ or __LINE__. This feature is useful for debugging, logging, and dynamically building directory paths.

Key points

Magic constants are written with two double bottom lines on the left and right
__FILE__ displays the file name, __LINE__ displays the line number
__DIR__ displays the directory where the files are located
Magic constants are automatically replaced by PHP values according to their context

Full lesson

Code examples and quizzes

Full lessons, code examples, and quizzes are available to subscribers. 5 questions.