Mastering Vim

Functions

Just like most other programming languages, Vim supports functions:

function AnimalGreeting(animal)  echo a:animal . ' says hello!'endfunction

In Vim, user-defined function names must start with a capital letter (unless they're within a script scope or behind a namespace). You'll get an error if you try to define a function starting with a lowercase letter.

You can try calling the function and you'll get the following output:

:call AnimalGreeting('cat')
cat says hello!

You can see that function arguments are accessed via the a: scope.

Functions, of course, can return values:

function! AnimalGreeting(animal)  return a:animal . ' says hello!'endfunction

Something to keep in mind is that in Vim a single script can get loaded multiple ...