Variadic functions can be called with any number of trailing arguments. The arguments can then be accessed as an array inside the function.
func sum(nums ...int)
sum(1, 2)
sum(1, 2, 3)
slice := []int{1, 2, 3, 4}
sum(slice)
Cannot mix a slice and individual args to a variadic function, e.g. sum(1, 2, slice)