Thanks a lot !

2009/7/5 Stephen Berman <stephen.berman@gmx.net>

> On Sun, 5 Jul 2009 12:25:00 +0800 waterloo <waterloo2005@gmail.com> wrote:
>
> > in 11.1.2 An Example: `print-elements-of-list' of `Instruction to
> > emacs lisp' , why C-u make the output not in minubuffer.
> > C-u is 4 by definition .
> > I can not understant why in the context.
> > can you explain more details or give some link ?
>
> I assume you are referring to this (in node
> (eintr)print-elements-of-list of the Introduction to Programming in
> Emacs Lisp):
>
> "Be sure to evaluate the last expression, `(print-elements-of-list
> animals)', by typing `C-u C-x C-e', that is, by giving an argument to
> `eval-last-sexp'.  This will cause the result of the evaluation to be
> printed in the `*scratch*' buffer instead of being printed in the echo
> area."
>
> That is, C-u is not a prefix argument of `print-elements-of-list' but of
> `eval-last-sexp', and its meaning is explained in the doc string of
> `eval-last-sexp', which you can read by typing `C-h f eval-last-sexp':
>
> ,----
> | eval-last-sexp is an interactive compiled Lisp function in
> `lisp-mode.el'.
> |
> | It is bound to C-x C-e.
> |
> | (eval-last-sexp eval-last-sexp-arg-internal)
> |
> | Evaluate sexp before point; print value in minibuffer.
> | Interactively, with prefix argument, print output into current buffer.
> | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> | Truncates long output according to the value of the variables
> | `eval-expression-print-length' and `eval-expression-print-level'.
> `----
>
> You need to use `eval-last-sexp' (or another evaluation method) because
> `print-elements-of-list' is not a command, i.e. an interactive function,
> since it lacks `(interactive)' in its definition.  So you cannot call it
> by typing `M-x print-elements-of-list' but have to explicitly evaluate
> it.
>
> Steve Berman
>