hasName {utils}

R Documentation

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

%in%, exists

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")

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