Removing empty lines in Notepad++

Question

How can I replace empty lines in Notepad++? I tried a find and replace with the empty lines in the find, and nothing in the replace, but it did not work; it probably needs r

Answer 1

I did not see the combined one as answer, so search for ^\s+$ and replace by {nothing}

^\s+$ means
  ^ start of line
  \s+ Matches minimum one whitespace character (spaces, tabs, line breaks)
  $ until end of line