nullp(3)

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

SYNOPSIS
int nullp(mixed arg);

DESCRIPTION
Return 1 if `arg' is null. 'arg' will be null in the following cases:

1.  it has not yet been initialized.

2.  it points to a destructed object.

3.  it is a function (formal) parameter that corresponds to a missing actual argument.

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