golang how to access interface fields
go, interface
Solution
An interface variable can be used to store any value that conforms to the interface, and call methods that are part of that interface. Note that you won't be able to access fields on the underlying value through an interface variable.
In this case, your `SearchItemsByUser` method returns an `interface{}` value (i.e. the empty interface), which can hold any value but doesn't provide any direct access to that value. You can extract the dynamic value held by the interface variable through a type assertion, like so:
dynamic_value := interface_variable.(typename)
Except that in this case, the type of the dynamic value is private to your SearchItemsByUser method. I would suggest making two changes to your code:
Define your `results` type at the top level, rather than within the method body.
Make `SearchItemsByUser` directly return a value of the `results` type instead of `interface{}`.
Problem
I have a function as below which decodes some json data and returns it as an interface ``` package search func SearchItemsByUser(r *http.Request) interface{} { type results struct { Hits hits NbHits int NbPages int HitsPerPage int ProcessingTimeMS int Query string Params string } var Result results er := json.Unmarshal(body, &Result) if er != nil { fmt.Println("error:", er) } return Result } ``` I'm trying to access the data fields ( e.g. Params) but for some reasons it says that the interface has no such field. Any idea why ? ``` func test(w http.ResponseWriter, r *http.Request) { result := search.SearchItemsByUser(r) fmt.Fprintf(w, "%s", result.Params) ```