Upgrade to PHP 7.1 on CentOS
Upgrading to PHP 7.1 on CentOS 7 is a simple four step process that's outlined below. Keep in mind that PHP 7 has a lot of changes, so it's always good to test this in a development environment before bringing this to production.
Step 1 - Enable the EPEL and Webtatic Repositories
Step 2 - Remove the Previous Version of PHP and Install 7
Remove the previous version of PHP, install PHP 7, and verify it installed correctly.
Step 3 - Optional Installs
Search for other PHP 7 packages you may need and install them.
Step 4 - Restart Apache
Restart the web server so it can see the changes.