How to stop Vim from automatically inserting the comment leader when Enter is pressed?

If I'm typing a comment in gVim like this

// this is 开发者_StackOverflow社区a comment

and I hit ENTER, it will automatically start the next line with //, so it looks like this:

// this is a comment
//

But usually I don't want to write more comments when using this commenting style. Can I stop gVim from automatically doing this, while still keeping the auto-completing of the /* .. */ commenting style?

To disable it while hitting ENTER in insert mode, do :set formatoptions-=r

To disable it while hitting o or O in normal mode, do :set formatoptions-=o

See :help 'formatoptions' and :help fo-table.

Alternatively, you can still press CTRL-U in insert mode if you want to delete characters from start of line till the cursor.

Another answer from mine since you don't want to have this triggered for /* … */ comments.

Use:

inoremap <expr> <enter> getline('.') =~ '^\s*//' ? '<enter><esc>S' : '<enter>'

For o and O:

nnoremap <expr> O getline('.') =~ '^\s*//' ? 'O<esc>S' : 'O'
nnoremap <expr> o getline('.') =~ '^\s*//' ? 'o<esc>S' : 'o'

To permanently disable this behavior, add autocmd FileType * set formatoptions-=r in your .vimrc/init.vim.

To have it disabled every time you use vim, open your .vimrc file and add the following line:

autocmd BufNewFile,BufRead * setlocal formatoptions-=r

Adding:

set fo-=ro

in ~/.vimrc was sufficient,

to disable Return and o/O keys in normal mode from autocommenting.

fo is a shorthand for formatoptions, and -= is to subtract certain keys while retaining the rest of the original value.

The value of fo can be shown using set fo? in command (ex) mode.

Issue help fo to read more about option in the vim's internal manual pages.