Cannot Use Isset On Expression, So Use What?

no-email (Damien Seguy), Damien Seguy
Fri, 27 Dec 2024 00:00:00 +0000

isset() works on data containers, such as variable, properties, array elements, but not on literal or constant values.
For literal values, it is recommended to avoid using isset, but make a comparison to ``null``, instead.
And of course, the error message is the same when the code uses both solutions at the same time. This may lead to confusion: the message suggests using ``null !== (NULL !== A)``, instead of ``isset(NULL !== A)``.