PHP 7.1 is nearing completion. A few days ago Release Candidate 1 was released. One of the areas that got some love from the developers is the type system. Pascal Martin wrote a blogpost about those changes.
One of the most important changes PHP 7.0 brought us last year was about typing, with the introduction of scalar type-declarations for functions/methods parameters and their return value. PHP 7.1 adds to those type-declarations, with several points that were missing in the previous version of the language.
iterable pseudo-type will sure come in handy.
If you want to know what's changed regarding error handling, Pascal has got that covered as well.