On this page
hasName Check for Name
  Description
hasName is a convenient way to test for one or more names in an R object.
Usage
hasName(x, name)
  Arguments
x | 
      Any object.  | 
     
name | 
      One or more character values to look for.  | 
     
Details
hasName(x, name) is defined to be equivalent to name %in% names(x), though it will evaluate slightly more quickly. It is intended to replace the common idiom !is.null(x$name). The latter can be unreliable due to partial name matching; see the example below.
Value
A logical vector of the same length as name containing TRUE if the corresponding entry is in names(x).
See Also
Examples
x <- list(abc = 1, def = 2)
!is.null(x$abc) # correct
!is.null(x$a)   # this is the wrong test!
hasName(x, "abc")
hasName(x, "a")
  Copyright (©) 1999–2012 R Foundation for Statistical Computing.
Licensed under the GNU General Public License.