What is the error (nvalid regular expression: missing /) and how to deal with it?

Question

Angular

angular 2
passed the video task
https://www.youtube.com/watch?v=Qjm1ZqjfYyw&index=...
and gave such an unpleasant error ((index):18 Error: SyntaxError: Invalid regular expression: missing /(…) )
how to deal with it?
can someone come across?

Answer 1

Mikhail Osher :
Mikhail Osher : the fact of the matter is that I haven't written any regular programs myself yet, I just got acquainted with the functionality from the video and tried to do the same on my LAN.