Examining core deprecations

In this section, we examine functions and usage that are deprecated in PHP 8. As the PHP language continues to mature, the PHP community is able to suggest to the PHP core development team that certain functions, classes, or even language usage should be removed. If two-thirds of the PHP development team vote in favor of a proposal, it's adopted for inclusion in a future release of the language.

In the case of functionality to be removed, it is not immediately taken out of the language. Instead, the function, class, method, or usage generates a Deprecation notice. This notice serves as a means to notify developers that this function, class, method, or usage will be disallowed in an as-yet-unspecified release of PHP. Accordingly, you must pay close attention to Deprecation notices. Failure to do so inevitably causes a code break in the future.

Tip

Starting with PHP 5.3, an official Request for Comments (RFC) process was initiated. The status...