Variable Names or Symbols, respectively

Description

as.symbol coerces its argument to be a symbol, or equivalently, a name. The argument must be of mode "character". as.name is an alias for as.symbol.

is.symbol (and is.name equivalently) returns TRUE or FALSE depending on whether its argument is a symbol (i.e., name) or not.

Usage

as.symbol(x)
is.symbol(y)

as.name(x)
is.name(y)

Arguments

Details

is.symbol is generic: you can write methods to handle specific classes of objects, see InternalMethods.

Note

The term “symbol” is from the LISP background of R, whereas “name” has been the standard S term for this.

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

call, is.language. For the internal object mode, typeof.

Examples

an <- as.name("arrg")
is.name(an) # TRUE
mode(an)   # name
typeof(an) # symbol