This help topic is for R version 0.60. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/base/html/formals.html
formals {base}R Documentation

Access to the Formal Arguments

Usage

formals(fun=sys.function(sys.parent()))

Value

If fun is a function then the formal argument list to that function is returned. If fun is a character string then the function with that name is found and used. If fun is not specified then the function calling formals is used.

It is currently not possible to set the formals of a function.

See Also

args

Examples

length(formals(lm))      # the number of formal arguments
names(formals(boxplot))  # formal arguments names

[Package base version 0.60 ]