Remove all white space in a file and replace them with a comma using Vim

Question

Anyone has an idea how to remove all white space and replace them with a comma , in a file using Vim ? File input example (words could be everywhere !):

Answer 1

First delete the blank lines:

:g/^\s*$/d

Then use a substitution (:s///) over each line (%) to replace all (g) continuous whitespace (\s\+) with a comma (,).

 :%s/\s\+/,/g