CODEWITHSUNDEEP
formatlispcommon-lisp
Terry
Terry

Reputation: 1232

How to prepend 0 to a list of integers in Lisp

I have a list of integers (3 11 7 26 5)

I wrote a function to prepend 0 to 1-digit numbers:

(defun beautify (list)
  (mapcar #'0-add list))

(defun 0-add (1digit)
  (format nil "~2,'0d" 1digit))

it outputs ("03" "11" "07" "26" "05")

However, I'd like to have (03 11 07 26 05)

How can I arrange it?

Upvotes: 3

Views: 233

Answers (1)

Rainer Joswig
Rainer Joswig

Reputation: 139311

CL-USER 10 > (format t "(~{~a~^ ~})" '("03" "11" "07" "26" "05"))
(03 11 07 26 05)

CL-USER 11 > (format t "(~{~2,'0d~^ ~})" '(3 11 7 26 5))
(03 11 07 26 05)

Upvotes: 6

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