(numberp)

(open)

(numberp item)

Determine whether an item is a number.

This function tests item to see if it is a number-either a real number or an integer. If item is a number, a T is returned. If not, nil is returned.

Examples

Code	Returns
(numberp 8)	T
(numberp 0.2653)	T
(numberp '(5 3.2 6))	nil
(numberp "Name")	nil

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(not item)

(type item)

LISP Compatibility

Programming Overview of LISP (LISt Processing) Language