So in Python and Ruby there is the splat operator (*) for unpacking an array as arguments. In Javascript there is the .apply() function. Is there a way of unpacking an array/slice as function arguments in Go? Any resources for this would be great as well!
Something along the lines of this:
func my_func(a, b int) (int) {
return a + b
}
func main() {
arr := []int{2,4}
sum := my_func(arr)
}
I do apologize if I'm making an syntactical/assorted mistakes. I'm new to Go.
You can use a vararg syntax similar to C:
package main
import "fmt"
func my_func( args ...int) int {
sum := 0
for _,v := range args {
sum = sum + v
}
return sum;
}
func main() {
arr := []int{2,4}
sum := my_func(arr...)
fmt.Println("Sum is ", sum)
}
Now you can sum as many things as you'd like. Notice the important ... after when you call the my_func function.
Running example: http://ideone.com/8htWfx
Either your function is varargs, in which you can use a slice with the ... notation as Hunter McMillen shows, or your function has a fixed number of arguments and you can unpack them when writing your code.
If you really want to do this dynamically on a function of fixed number of arguments, you can use reflection:
package main
import "fmt"
import "reflect"
func my_func(a, b int) (int) {
return a + b
}
func main() {
arr := []int{2,4}
var args []reflect.Value
for _, x := range arr {
args = append(args, reflect.ValueOf(x))
}
fun := reflect.ValueOf(my_func)
result := fun.Call(args)
sum := result[0].Interface().(int)
fmt.Println("Sum is ", sum)
}
No, there's no direct support for this in the language. Python and Ruby, as well as Javascript you're mentioning; are all dynamic/scripting languages. Go is way more closer to, for example, C than to any dynamic language. The 'apply' functionality is handy for dynamic languages, but of little use for static languages like C or Go,
来源：https://stackoverflow.com/questions/17555857/go-unpacking-array-as-arguments