问题
I tried to find a lisp function to convert between numbers and strings and after a little googling I fond a function with the same name. when I entered (itoa 1) SLIME printed:
Undefined function ITOA called with arguments (1) .
How can I do the conversion?
回答1:
From number to string:
(write-to-string 5)
"5"
you may transform a string to any numerical notation:
(write-to-string 341 :base 10)
"341"
From string to number:
(parse-integer "5")
5
with some trash
(parse-integer " 5 something not a number" :junk-allowed t)
5
Or use this:
(read-from-string "23 absd")
23
回答2:
A heavyweight solution is to use FORMAT:
[2]> (format nil "~A" 1)
"1"
There is also WRITE-TO-STRING:
[3]> (write-to-string 10)
"10"
回答3:
FYI: I believe (itoa #) is only a function in AutoLISP - the LISP variant embedded in AutoCAD drafting software. AutoLISP has far fewer functions than Common Lisp and sometimes identical functions with a different name or functions with the same name that operate differently.
That's probably why it didn't work for you. I use AutoLISP regularly and (itoa #) would do exactly what you want there.
来源：https://stackoverflow.com/questions/16220607/converting-number-to-string-in-lisp