.\"determine whether or not a given variable is null.
.TH nullp 3

.SH NAME
nullp() - determine whether or not a given variable is null.

.SH SYNOPSIS
int nullp(mixed arg);

.SH DESCRIPTION
Return 1 if `arg' is null.  'arg' will be null in the following
cases:
.TP
1.
it has not yet been initialized.
.TP
2.
it points to a destructed object.
.TP
3.
it is a function (formal) parameter that corresponds to a missing actual
argument.

.SH SEE ALSO
undefinedp(3), mapp(3), stringp(3), pointerp(3), objectp(3), intp(3).