vimscript call vs. execute

Question

In vimscript, what is the difference between call and execute? In what scenarios / use cases should I use one vs the other?

(Disclaimer, I am aware of the extensive online help available within vim - I am seeking a concise answer to this specific question).

Answer 1

From the experience of writing my own plugins and reading the code of others:

:call is for calling functions, e.g.:

function! s:foo(id)
    execute 'buffer' a:id
endfunction

let target_id = 1
call foo(target_id)

:execute is used for two things:

1. Construct a string and evaluate it. This is often used to pass arguments to commands:

   execute 'source' fnameescape('l:path')
   

2. Evaluate the return value of a function (arguably the same):

   function! s:bar(id)
       return 'buffer ' . a:id
   endfunction
   
   let target_id = 1
   execute s:bar(target_id)