On the Kinsta blog there's a post detailing some of the new features that are coming in the next release in the PHP 7 series - PHP 7.10.

The newest version of PHP – 7.1.0 – is already at RC6 (Release Candidate 6) status, which means it will be out soon. After a huge update that took PHP from 5.6 straight to 7.0 increasing speeds considerably, PHP is now focusing on core language features that will help all of us write better code. In this article I’ll take a look at the major additions and features of PHP 7.1.0 which is just around the bend.

Their list of items includes:

• nullable types
• iterable and void returns
• the use of keys in lists
• number operators and malformed numbers

Each item in the list includes a brief description and some example code show the feature in use where it makes sense. If you're not overly familiar with what's coming in PHP 7.1 this is a great guide.