Function: zerop

zerop is a byte-compiled function defined in subr.el.gz.

Signature

(zerop NUMBER)

Documentation

Return t if NUMBER is zero.

Other relevant functions are documented in the number group.

View in manual

Shortdoc

;; number
(zerop 0)
    => t

Source Code

;; Defined in /usr/src/emacs/lisp/subr.el.gz
(defun zerop (number)
  "Return t if NUMBER is zero."
  ;; Used to be in C, but it's pointless since (= 0 n) is faster anyway because
  ;; = has a byte-code.
  (declare (ftype (function (number) boolean))
           (pure t) (side-effect-free t)
           (compiler-macro (lambda (_) `(= 0 ,number))))
  (= 0 number))