Join Curves
Command
Join
Shortcut
J
Button
In Command Bar 
Join Curves at connecting points.
Basic Usage
- Select the Curves you want to join.
- Press J.
- Curves are joined.
❗
Note
To join two Curves, their endpoints must be perfectly aligned.
When they are perfectly aligned, the Points will turn blue-green. If they appear purple, they are not aligned. To ensure a precise alignment, see Object Snaps.