![[LISPWORKS]](../Graphics/LWSmall.gif)
![[Common Lisp HyperSpec (TM)]](../Graphics/CLHS_Sm.gif) 
 ![[Previous]](../Graphics/Prev.gif)
![[Up]](../Graphics/Up.gif)
![[Next]](../Graphics/Next.gif)
Syntax:
digit-char-p char &optional radix => weight
Arguments and Values:
char---a character.
radix---a radix. The default is 10.
weight---either a non-negative integer less than radix, or false.
Description:
Tests whether char is a digit in the specified radix (i.e., with a weight less than radix). If it is a digit in that radix, its weight is returned as an integer; otherwise nil is returned.
Examples:
 (digit-char-p #\5)    =>  5
 (digit-char-p #\5 2)  =>  false
 (digit-char-p #\A)    =>  false
 (digit-char-p #\a)    =>  false
 (digit-char-p #\A 11) =>  10
 (digit-char-p #\a 11) =>  10
 (mapcar #'(lambda (radix) 
             (map 'list #'(lambda (x) (digit-char-p x radix)) 
                  "059AaFGZ"))
         '(2 8 10 16 36))
 =>  ((0 NIL NIL NIL NIL NIL NIL NIL)
     (0 5 NIL NIL NIL NIL NIL NIL)
     (0 5 9 NIL NIL NIL NIL NIL)
     (0 5 9 10 10 15 NIL NIL)
     (0 5 9 10 10 15 16 35))
 
Affected By:
None. (In particular, the results of this predicate are independent of any special syntax which might have been enabled in the current readtable.)
Exceptional Situations: None.
See Also:
Notes:
Digits are graphic characters.
![[Starting Points]](../Graphics/StartPts.gif)
![[Contents]](../Graphics/Contents.gif)
![[Index]](../Graphics/Index.gif)
![[Symbols]](../Graphics/Symbols.gif)
![[Glossary]](../Graphics/Glossary.gif)
![[Issues]](../Graphics/Issues.gif)