map.vs.struct.safeparser

safejsonmap.go

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
	// Create a map to parse the JSON
	var data map[string]interface{}

	// Define a JSON string
	j := `{"name":"example","numbers":[1,2,3,4],"nested":{"isit":true,"description":"a nested json"}}`

	// Parse our JSON string
	err := json.Unmarshal([]byte(j), &data)
	if err != nil {
		fmt.Printf("Error parsing JSON string - %s", err)
	}

	// Print out the JSON Name
	n, ok := data["name"].(string)
	if !ok {
		// set to default
		n = "default"
	}
	fmt.Printf("Name is %s\n", n)

	// Print out the JSON Numbers
	var nums []int
	i, ok := data["numbers"].([]interface{})
	if ok {
		for _, v := range i {
			x, ok := v.(float64)
			if !ok {
				// set to default
				nums = []int{}
				break
			}
			nums = append(nums, int(x))

		}
	}
	fmt.Printf("Numbers are")
	for _, v := range nums {
		fmt.Printf(" %d", v)
	}
	fmt.Printf("\n")

	// Print out the JSON description
	desc := "Description Not Found"
	d, ok := data["nested"].(map[string]interface{})
	if ok {
		desc, ok = d["description"].(string)
		if !ok {
			desc = ""
		}
	}
	fmt.Printf("Description is %s", desc)
}