.TH isdigit() "" "" "ctype Function (libc)"
.PC "Check if a character is a numeral"
\fB#include <ctype.h>\fR
\fBint isdigit(\fIc\^\fB) int \fIc\^\fB;\fR
.PP
.B isdigit()
tests whether
the argument \fIc\fR is a numeral (\fB0-9\fR).
It returns a number other than zero
if \fIc\fR is a numeral, and
zero if it is not.
.B isdigit()
assumes that \fIc\fR is an ASCII character or \fBEOF\fR.
.SH Example
For an example of how to use this macro, see the entry for
.BR ctype.h .
.SH "See Also"
.Xr "ASCII," ascii
.Xr "libc" libc
.br
\*(AS, \(sc7.3.1.4
.br
\*(PX Standard, \(sc8.1
