Summary of Emacs LISP

Emacs has three lisp modes. The command name is as follows:

Emacs-lisp-mode for Emacs LISPCode(File name. emacs or suffix. El)
LISP-mode is used to edit the lisp code (suffix. l or. LISP) of another lisp system)
LISP-interaction-mode is used to edit and run Emacs lisp code (interactive mode)
This article only discusses the lisp-interaction-mode.

By default, * Scratch * is in this mode. A file name without a suffix usually enters the lisp interaction mode for Emacs. Of course, you can use the auto-mode-alist variable to set it.

C-x C-E: run the selected text

LISP is a collection language that cannot be nested with parentheses.
The following are differences:
(X); the interpreter parses the brackets and calculates the result.
'(X); Do not parse

C-H v
C-h f look at the function