numberp
type: predicate function (subr) location: built-in source file: xlbfun.c Common LISP compatible: yes supported on: all machines
SYNTAX
(numberp <expr> ) <expr> - the expression to check
DESCRIPTION
The NUMBERP predicate checks if an <expr> is a number. T is returned if <expr> is an integer or floating point number, NIL is returned otherwise.
EXAMPLES
(numberp 1) ; returns T - integer (numberp 1.2) ; returns T - float (numberp '1) ; returns T - still an integer (numberp #x034) ; returns T - readmacro produces ; an integer ; (numberp 'a) ; returns NIL - symbol (numberp #\a) ; returns NIL - character (numberp NIL) ; returns NIL - NIL (numberp #(0 1 2)) ; returns NIL - array