| nargs {base} | R Documentation |
When used inside a function body, nargs returns the number of
arguments supplied to that function, including positional
arguments left blank.
nargs()
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
tst <- function(a, b = 3, ...) {nargs()}
tst() # 0
tst(clicketyclack) # 1 (even non-existing)
tst(c1, a2, rr3) # 3
foo <- function(x, y, z, w) {
cat("call was", deparse(match.call()), "\n")
nargs()
}
foo() # 0
foo(,,3) # 3
foo(z=3) # 1, even though this is the same call
nargs()# not really meaningful