What is the return value for visual block mode in vimscript?

Question

I'm trying to display the current mode of vim on the status line by mapping the return value of mode function by using a dictionary:

let g:modeMap={
    \ 'n'      : 'Normal',
    \ 'i'      : 'Insert',
    \ 'R'      : 'Replace',
              ...
    \ 'v'      : 'Visual',
    \ 'V'      : 'Visual Line',
    \ '\<C-V>' : 'Visual Block'
    \}

set laststatus=2
set statusline=%{g:modeMap[mode()]}

It works well for almost all modes, however it throws the following error message in case of switching to visual block mode:

E716: Key not present in Dictionary: ^V 

I've also tried the string <\C-V> found here, CTRL-V found here and ^V which was written out in the error message but neither of them was correct.

Tested with versions:

• Vim 7.4, Ubuntu 16.04
• Vim 8.1, Debian 9

Answer 1

'\<C-V>' -- is a literal string in VimL.

You must use double quotes to make the substitution work: "\<C-V>".