Currently the upgrade path for PHP 7 is managed by Ondřej Surý (note the utf-8 characters in his name), and PPA (Personal Package Archives) have been made available for ubuntu.
Installation, or upgrade begins with adding the PPA to apt, so that apt knows where to look for the packages.
Due to the UTF-8 characters in the name of the maintainer, a language pack may be required.
sudo LC_ALL=en_US.UTF-8 add-apt-repository ppa:ondrej/php
From here, the install, or upgrade is the same as with any apt-get installation. First, ensure the system is up to date.
The update to PHP 7.
In PHP 7, the old, deprecated mysql_* extensions have been removed. If you are using MySQL you will need this.
All done. To test if the isntallation was successful, simply test the version.
PHP 7.0.2-2+deb.sury.org~trusty+1 (cli) ( NTS )
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