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

mapp(3),  stringp(3),  pointerp(3),  objectp(3),  intp(3),  bufferp(3),
floatp(3), functionp(3), undefinedp(3), errorp(3)