How do I Join the line above after current line?

join, lines, vim

Solution

There are many ways to do it. One would be… deleting the line above and appending it to the end of the line below:

k move up one line
^ move to the first printable character
y$ yank to the end of the line
"_d get rid of the now useless line by deleting it into the black hole register
$ move to the end of the line
p put the deleted text

Problem

I know these commands in Vim: J : Join line below after current line -J : Join current line after line above but how do I join the line above after current line?

Original source