When editing Emacs Lisp code, you can use the commands
C-h f (
C-h v (
describe-variable) to view the built-in documentation for the Lisp functions and variables that you want to use. See Name Help.
ElDoc is a buffer-local minor mode that helps with looking up Lisp documentation. When it is enabled, the echo area displays some useful information whenever there is a Lisp function or variable at point; for a function, it shows the argument list, and for a variable it shows the first line of the variable’s documentation string. To toggle ElDoc mode, type
M-x eldoc-mode. There’s also a Global ElDoc mode, which is turned on by default, and affects buffers, such as ‘
*scratch*’, whose major mode is Emacs Lisp or Lisp Interaction (
M-x global-eldoc-mode to turn it off globally).