Unable to decode int field from JSON - json

Question

My goal is to read JSON file. Although the following program reads the file fine, the id field value is incorrect. id field value is 0 for all the objects read.
Example JSON file contents:
{
"users" : [
{
"id" : "1",
"name" : "Matt Hayden"
},
{
"id" : "2",
"name" : "David Warner"
},
]
}
JSON file reader program in Golang
type Schema struct {
Id int `json:"id"`
Name string `json:"name"`
}
func reader() {
fileName := "./input.json"
jsonFile, fileErr := os.Open(fileName)
if fileErr != nil {
_ = errors.Errorf("failed to open file %s : %v", fileName, fileErr)
}
defer jsonFile.Close()
bytesRead, readErr := ioutil.ReadAll(jsonFile)
if readErr != nil {
_ = errors.Errorf("failed to read json file %s : %v", fileName, readErr)
}
var sch Schema
unMarshalErr := json.Unmarshal(bytesRead, &sch)
if unMarshalErr != nil {
_ = errors.Errorf("failed to unmarshal JSON bytes : %v", unMarshalErr)
}
fmt.Printf("%+v", sch)
}
Actual output:
{Users:[{Id:0 Name:Matt Hayden} {Id:0 Name:David Warner}]}
Expected output:
{Users:[{Id:1 Name:Matt Hayden} {Id:2 Name:David Warner}]}

Answer 1

You can add an extra type in your JSON struct tag. Take a look at the Marshal documentation here.
Example: https://play.golang.org/p/VqZu9SrnpW4
package main
import (
"encoding/json"
"fmt"
"reflect"
)
type Response struct {
Users []User `json:"users"`
}
type User struct {
ID int `json:"id,string"`
Name string `json:"name"`
}
func main() {
r := &Response{}
err := json.Unmarshal([]byte(`{
"users" : [
{
"id" : "1",
"name" : "Matt Hayden"
},
{
"id" : "2",
"name" : "David Warner"
}
]
}`), &r)
if err != nil {
panic(err)
}
fmt.Printf("%#v \n", r)
fmt.Printf("Type of ID is %s \n", reflect.TypeOf(r.Users[0].ID)) // int
}