Elisp Arithmetics
Table of Contents
1. Truncate, Round, Ceiling, Floor
;; to int
(truncate 3.5) ; => 3
(round 3.5) ; => 4
(ceiling 3.5) ; => 4
(floor 3.5) ; => 3
2. Test If a Number is Integer or Float
Returns t if yes, nil if not.
(integerp 2) ; t
(integerp 2.) ; t
(integerp 2.0) ; nil
(floatp 2) ; nil
(floatp 2.) ; nil
(floatp 2.0) ; t
3. Conversion between Numbers and Strings
(number-to-string 3) ; => "3"
(string-to-number "3") ; => 3
4. Equality
We use = equal sign to evaluate equality, arguments can be integers and flaots. We use /= to evaluate inequality.