This is a [[wp:command-line interpreter|command-line interpreter]] that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a ''command mode'', a ''[[wp:read-eval-print loop|read-eval-print loop]]'' (REPL), or a ''shell''.
Then, as a small example of its use, interactively create a function of two strings and a separator that returns the strings separated by two concatenated instances of the separator (the 3<sup>rd</sup> argument).
;Example:
<big> f('Rosetta', 'Code', ':') </big>
should return
<big> 'Rosetta::Code' </big>
;Note:
This task is ''not'' about creating your own interactive mode.
