How to refer to a specific line or range of lines in github?

Question

If you want to add a reference to a specific line or a range of lines, it would be nice to get an URL that does that.

Answer 1

If you go the the file (or version of the file you want to refer to), click the line number (or hold shift down to select a range).

=> you will see that the URL changes (it adds something like #L21-L23 to the URL).

Just copy the URL.