---
layout: doc
title: general / nullp
---
# nullp

### 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)

