Vim
 

wondering how to do a certain conditional statement in bash using vim ex if the argument is a 1, the script will echo january.

vim and ex are interactive editors. They can't be used to execute statements conditionally or print strings.

To output something conditionally, you can use the if clause:
Or shorter:
Use the Bash resources in my signature to explore the case statement.

Well, actually Vim can execute scripts with vim -s scriptname.vim. Those scripts have nothing to do with bash though. They are written in Vimscript. It's a full-blown scripting language with conditionals and printing commands among others. For an example of such a script, see your /etc/vimrc or /etc/vim/vimrc (different distros have different conventions as to where they put system-wide Vim configuration).

Or just start Vim like this:
and watch the last screen line after start.