Nested Map golang tutorial

nestedmap.go

package main

import (
"fmt"
"encoding/json"
)
type ProjectAttributes struct{
ProjectId string
Attributes map[string]interface{}
}
func main() {
fmt.Println("Hello, playground")
phase:=make(map[string]string)
phase["p1"]="60"
phase["p2"]="60"

//convert phases to json string
phasesAsString,_:=json.Marshal(phase)
if(phasesAsString==nil){
fmt.Println("phasesAsString nil")
}


//Attributes started
//var mp=map[string]interface{}
mp:=make(map[string]interface{})//map[string]string)


//mp["attributes"]=make(map[string]string)
mp["phase"]=phase
mp["budget"]="40"
//Add Phases to Attributes
//mp=phase//string(phasesAsString)
//mp["budget"]="20"



//Make custom struct
var projectAttributes ProjectAttributes
projectAttributes.ProjectId="1"
projectAttributes.Attributes=mp

bt,_:=json.Marshal(projectAttributes)
if(bt==nil){
fmt.Println("bt nil")
}
fmt.Printf("Json  %v",string(bt))
pt:=ProjectAttributes{}
if e:=json.Unmarshal(bt,&pt);e!=nil{
	fmt.Printf("ERR %v",e.Error())
}
fmt.Printf("Obj %v",pt)

}