The main version of PHP 7.0 was released a year ago. It laid the foundations for future PHP development (PHPNG) by adding outstanding features, enhanced performance, high speed and reduced memory usage.
What’s new in PHP 7.1?
Here are some of the most remarkable improvements and features:
- Nullable types; (additional option for parameters or function returns to be of NULL);
- Void return type (declares that this function doesn’t return any value, including ‘NULL’);
- Iterable pseudo-type;
- Class constant visibility modifiers – make class-constants (such as private, protected, public) visible;
- Square bracket syntax for list() – is a new syntax for list() (with  syntax);
- improved method for catching exceptions (Catching Multiple Exception Types);
- Deprecated features:
- and many more.
Activating PHP 7.1
You can also enable a different PHP version for a specific directory by modifying the .htaccess file.
For the time being Joomla! and Drupal have not yet officially announced if they will support the new PHP version. This will probably happen when their next versions are released. WordPress 4.6 is not PHP 7.1 compatible but the new 4.7 version is fully compatible.
Before switching to 7.1 you would better make sure that your website along with the theme and plugins used can properly work with the latest PHP version. If you have already enabled 7.1 and notice that а certain functionality does not work, you can always downgrade to an older PHP version from PHP Manager by SuperHosting that is available in your cPanel.