Null Objects

DESCRIPTION:

Creates or tests for NULL objects.

USAGE:

null() 
as.null(x) 
is.null(x) 

REQUIRED ARGUMENTS:

x
a S-PLUS object.

VALUE:

null and as.null always return NULL.

is.null returns TRUE or FALSE, according as x is or is not NULL.

DETAILS:

Both is.null and as.null are generic; currently there are no methods defined for either of them.

WARNING:

An object can be of length 0 and not be NULL, see the examples section.

SEE ALSO:

.

EXAMPLES:

is.null(character(0)) # returns FALSE