I was testing some go array initialization and general usage but I can not figure out why can not expand an array initialized with a defined length?
package main
func main() {
arr0 := []int{1, 2, 3} //
add(arr0...) // OK
arr1 := [3]int{1, 2, 3} //
slice := arr1[:] //
add(slice...) // OK
arr2 := [3]int{} //
arr2[0] = 1 //
arr2[1] = 2 //
arr2[3] = 3 //
add(arr2...) // cannot use arr2 (type [3]int) as type
// []int in argument to add
}
func add(terms ...int) (sum int) {
for _, term := range terms {
sum += term
}
return
}
As other said:
[n]type - Array (fixed size)
[]type - Slice
A quick solution for your case would be a simple conversion from array to slice.
add(arr2[:]...)
That will just make it a slice pointing to the storage of arr2 (not a copy)
when use the operator ... as a tail, such as T.... T should always be slice.