type JobTitles struct {
Titles []string `json:"titles"`
}
chiefTitles := []string{"CEO", "CFO", null, "CMO"}
jsonOut := JobTitles{chiefTitles}
In the code above, I would like to be able to send null as one of the values in my json string array. However, the above will not compile and if I add double quotes to null it becomes a string not the value null.
How can I send null in my json response in GO?
This article seems to help, but looks to be the inverse of my question..
In order to represent that type with the value 'null' it would have to be a pointer. The problem isn't that you can't use null but rather that a string can't have that value. Here is a quick example I made in the playground; https://play.golang.org/p/SXO5sBl2mR
package main
import "fmt"
import "encoding/json"
type Test struct {
A *string
B *string
}
func main() {
s := "Something"
t := Test{A:&s, B:nil}
b, err := json.Marshal(t)
if err != nil {
fmt.Println(err)
}
fmt.Println(string(b))
}
As DaveC mentioned using pointers makers the initilization a bit more cumbersome but you can use the same type of constructs I have above; declare a string, use the & that string in the composite literal.
You will have to use *string instead, and create a helper function to make it easier, something along the lines of:
func main() {
chiefTitles := []*string{sP("CEO"), sP("CFO"), nil, sP("CMO")}
b, _ := json.Marshal(JobTitles{chiefTitles})
fmt.Println(string(b))
}
type JobTitles struct {
Titles []*string `json:"titles"`
}
func sP(s string) *string {
return &s
}