is.empty: Checks if an object is empty (e.g: of zero length)

In installr: Using R to Install Stuff (Such As: R, 'Rtools', 'RStudio', 'Git', and More!)

Description

Checks if an object is empty (e.g: of zero length) and returns TRUE/FALSE

Usage

is.empty(x, mode = NULL, ...)

Arguments

x	an object
mode	is the object an empty (zero length) object of this mode (can be "integer", "numeric", and so on...)
...	none are available.

Details

Uses identical and avoids any attribute problems by using the fact that it is the empty set of that class of object and combine it with an element of that class.

Value

Returns TRUE/FALSE if the object is empty or not.

Author(s)

James (http://stackoverflow.com/users/269476/james)

Source

http://stackoverflow.com/questions/6451152/how-to-catch-integer0

See Also

integer, identical

Examples

is.empty(integer(0)) #TRUE
is.empty(0L)         #FALSE
is.empty(numeric(0)) #TRUE
is.empty(NA) # FALSE 
is.empty(FALSE) # FALSE 
is.empty(NULL) # FALSE (with a warning)

a <- which(1:3 == 5)
b <- numeric(0)
is.empty(a)
is.empty(a,"numeric")
is.empty(b)
is.empty(b,"integer")

installr documentation built on May 30, 2017, 3:26 a.m.