strict json parser in golang

In Go, I have some JSON from third-party API and then I'm trying to parse it:

b := []byte(`{"age":21,"married":true}`)
var response_hash map[string]string
_ = json.Unmarshal(b, &response_hash)

But it fails (response_hash becomes empty) and Unmarshal can handle only JSON with quotes:

b := []byte(`{"age":"21","married":"true"}`)
var response_hash map[string]string
_ = json.Unmarshal(b, &response_hash)

Is there any way to read the first version of JSON from third-party API?

Go is a strongly typed language. You need to specify what types the JSON encoder is to expect. You're creating a map of string values but your two json values are an integer and a boolean value.

Here's a working example with a struct.

http://play.golang.org/p/oI1JD1UUhu

package main

import (
	"fmt"
	"encoding/json"
	)

type user struct {
	Age int
	Married bool
}

func main() {
	src_json := []byte(`{"age":21,"married":true}`)
	u := user{}
	err := json.Unmarshal(src_json, &u)
	if err != nil {
		panic(err)
	}
	fmt.Printf("Age: %d\n", u.Age)
	fmt.Printf("Married: %v\n", u.Married)
}

If you want to do it in a more dynamic manner you can use a map of interface{} values. You just have to do type assertions when you use the values.

http://play.golang.org/p/zmT3sPimZC

package main

import (
	"fmt"
	"encoding/json"
	)

func main() {
	src_json := []byte(`{"age":21,"married":true}`)
	// Map of interfaces can receive any value types
	u := map[string]interface{}{}
	err := json.Unmarshal(src_json, &u)
	if err != nil {
		panic(err)
	}
	// Type assert values
	// Unmarshal stores "age" as a float even though it's an int.
	fmt.Printf("Age: %1.0f\n", u["age"].(float64))
	fmt.Printf("Married: %v\n", u["married"].(bool))
}