| hasName {utils} | R Documentation |
hasName is a convenient way to test for one or more names
in an R object.
hasName(x, name)
x |
Any object. |
name |
One or more character values to look for. |
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$name). The latter can be unreliable due to partial
name matching; see the example below.
A logical vector of the same length as name containing
TRUE if the corresponding entry is in names(x).
x <- list(abc = 1, def = 2) !is.null(x$abc) # correct !is.null(x$a) # this is the wrong test! hasName(x, "abc") hasName(x, "a")