Variable arguments and overloading methods

Question

If I have overloaded methods, say:
double foo(int... args) and double foo(double... args)
I can do:
int[] val = {1,2,3,4,5};
double dd = foo(val);
I don't get a compiler error, but if I do:
int a=1, b=2, c=3, d=4, e=5;
double dd = foo(a,b,c,d,e);
java complains that foo(int..) and foo(double...) are ambiguous.
Why?

Answer 1

jverd wrote:
jverd wrote:
>
[JLS 15.12.2.4 Phase 3: Identify Applicable Variable Arity Methods|http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#15.12.2.4]
and
[JLS 15.12.2.5 Choosing the Most Specific Method|http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#15.12.2.5]
I don't feel like unravelling those in detail right now, but I think it's that an int[] cannot be promoted to a double[], so there's no ambiguity there, but an int can be promoted to a double, so that's ambiguous.Just because two versions apply doesn't make it ambiguous. It's ambiguous when there isn't a "most specific method" demo:
public class Example {
    static void f(String x, Object y) {} //version 1
    static void f(Object x, String y) {} //version 2
    static void f(Object x, Object y) {} //version 3
    public static void main(String[] args) {
        String s = "string";
        Object o = "object";
        f(s, o);
        f(0, s);
        f(s, s); //ambiguous!
}I define three versions of f. In the first invocation, versions 1 and 3 apply but 1 is the most specific.
In the second invocation versions 2 and 3 apply but 2 is the most specific.
In the third invocation versions 1 and 2 apply but neither is the more specific than the other, so the call is ambiguous.