nargs {base}

R Documentation

The Number of Arguments to a Function

Description

When used inside a function body, nargs returns the number of arguments supplied to that function, including positional arguments left blank.

Usage

nargs()

See Also

args, formals and sys.call.

Examples

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

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