How to select non contiguous lines of code in Notepad++?

from the help:

If a stream area is selected, it is possible to add another, disjoint area by Ctrl-clicking its start point and moving the mouse to the end point. More than one extra selection can be added this way. (Multi-Editing should be enabled in Preferences)

Source: http://npp-community.tuxfamily.org/documentation/selecting-text

tl;dr - Settings -> Preferences -> Editing -> Multi-Editing Settings -> Enable, then Ctrl-Click for each section