how to make valid parameter to the variadic function

Question

I have made the following variadic function for the counter task:

func count (num int, data ...int, ch chan int) {
var counter int
for _, v := range data {
switch v {
case num :
counter++
}
}
ch <- counter
}
...
go count(num, data[:len(data)/2], ch1)
...

Why the second parameter is not accepted?

Answer 1

The variadic parameter needs to be the last parameter in the func, otherwise the number of required arguments is ambiguous. Try this instead;
func (num int, ch chan int, data ...int){...code...}

Then you also need to spread the arguments like;
go count(num, ch1, data[:len(data)/2]...)

Answer 2

Thank you so much for the answer. I never would have guessed about putting ellipsis here: go count(num, ch1, data[:len(data)/2]...).