Simple golang app gives below error
.\test.go:13: cannot use ds (type Data_A) as type []interface {} in field value
for below code
package main
type Data_A struct {
a string
}
type DTResponse struct {
Data []interface{} `json:"data"`
}
func main() {
ds := Data_A{"1"}
dtResp := &DTResponse{ Data:ds}
print(dtResp)
}
I would like to have a struct with slice variable of any type. Using struct{} gives the same error.
In Java I could use Object as it is the parent object of any object. But I could not find such one in golang.
Any help would be appreciated.
Yes, as a slice of interface{} which can hold any arbitrary value.
var s = []interface{}{1, 2, "three", SomeFunction}
fmt.Printf("Hello, %#v
", s)
Output:
Hello, []interface {}{1, 2, "three", (func())(0xd4b60)}
https://play.golang.org/p/MQMc689StO
But I do not recommend simulate dynamic-typed languages (like Python, JavaScript, PHP, etc) this way. Better to use all static-typed benefits from Go, and leave this feature as a last resort, or as a container for user input. Just to receive it and convert to strict types.
Go is a strongly explicitly typed language thus you can't substitute an object of one type with another (it is already compiled in this way). Also when you do type Data_A struct {... you define new type named Data_A. []interface{} and Data_A are completely different types and these types (like any other) are not interchangeable. Note, even interface{} is not interchangeable with anything. You can pass any type in a function like this func f(a interface{}){... but inside the function you will have exactly interface{} type and you should assert it to use properly.
package main
type Data_A struct {
a string
}
type DTResponse struct {
Data Data_A `json:"data"`
}
func main() {
ds := Data_A{"1"}
dtResp := &DTResponse{ Data:ds}
print(dtResp)
}
package main
type DTResponse struct {
Data []interface{} `json:"data"`
}
func main() {
ds := []interface{}{"1"}
dtResp := &DTResponse{ Data:ds}
print(dtResp)
}
Possibly the cause of confusion: struct is not slice or array.