Script to compile php 7 on Slackware 14.02
$git clone https://github.com/rumbler/php7-SlackBuild
$cd php7-SlackBuild
$./php7Build.sh
Assuming everything happened according to plan (the compile finished without errors), the finished package should be in the directory declared as "OUTPUT" in the SlackBuild script (this defaults to the /tmp directory). Use installpkg to install it; you'll probably want to move it to some other location for safekeeping after it's installed.
Enjoy