Find what filetype is loaded in vim

&filetype for script usage

Minimal example:

echo &filetype

More realistic usage example:

if &filetype ==# 'c' || &filetype ==# 'cpp'
  setlocal noexpandtab
endif

& syntax works for all options: https://vi.stackexchange.com/questions/2569/how-do-i-check-the-value-of-a-vim-option-in-vimscript

You can also add the filetype to your status line or window title using the %y and %Y items. See

:help 'statusline'
:help 'titlestring'

When I wanted to find the filetype it was because I was having the .ipy extension modifying an ipython script. The above Q&A worked great to see that the ipython extension was not being treated as python (somewhat obvious). Thus I wanted to force set the filetype, and I found this from the ever helfpul vim site. http://vim.wikia.com/wiki/Forcing_Syntax_Coloring_for_files_with_odd_extensions

Adding the below to your .vimrc works

au BufRead,BufNewFile *.ipy set filetype=python

:set filetype?