digit-char-p

digit-char-p Function

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.)

See Also:

alphanumericp

Notes:

Digits are graphic characters.

Expanded Reference: digit-char-p

tip

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(digit-char-p )