Backward Incompatible¶
A feature is backward incompatible when it cannot work with a previous version, and requires a specific version, or more recent.
For example, the function str_contains is backward incompatible, as it was introduced in version 8.0, and is not available in previous versions.
The keyword throw can be used within expressions since PHP 8.0. In older versions, throw was available, but needed to be an instruction on its own.
The contrary of a backward incompatible feature is forward compatible.
<?php
check() or throw new Exception('Check failed!');
?>
Related : Forward Compatible, Backward Compatible, Legacy
Added in PHP 8.0
