Go: Query a REST API and convert the JSON payload to a struct

rest_api_json_to_struct.go

package main

import (
    "encoding/json"
    "net/http"
    "fmt"
)

// 20210926113330
// https://api.coindesk.com/v1/bpi/currentprice.json
// API Response Body
// {
//   "time": {
//     "updated": "Sep 26, 2021 15:33:00 UTC",
//     "updatedISO": "2021-09-26T15:33:00+00:00",
//     "updateduk": "Sep 26, 2021 at 16:33 BST"
//   },
//   "disclaimer": "This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org",
//   "chartName": "Bitcoin",
//   "bpi": {
//     "USD": {
//       "code": "USD",
//       "symbol": "$",
//       "rate": "43,327.2067",
//       "description": "United States Dollar",
//       "rate_float": 43327.2067
//     },
//     "GBP": {
//       "code": "GBP",
//       "symbol": "£",
//       "rate": "31,660.3597",
//       "description": "British Pound Sterling",
//       "rate_float": 31660.3597
//     },
//     "EUR": {
//       "code": "EUR",
//       "symbol": "€",
//       "rate": "36,968.2892",
//       "description": "Euro",
//       "rate_float": 36968.2892
//     }
//   }
// }

type Time struct {
  Updated string `json:updated`
  UpdatedISO string `json:updatedISO`
  Updateduk string `json:updateduk`
}

type CUR struct {
  Code string `json:code`
  Symbol string `json:symbol`
  Rate string `json:rate`
  Description string `json:description`
  Rate_float float32 `json:rate_float`
}
type BPI struct {
  USD CUR
  GBP CUR
  EUR CUR
}
type Response struct {
  Time Time `json:time`
  ChartName string `json:chartName`
  Disclaimer string `json:disclaimer`
  Bpi BPI `json:bpi`
  

}

func main() {
  resp, err := http.Get("https://api.coindesk.com/v1/bpi/currentprice.json")

  if err != nil {
    panic(err)
  }
  defer resp.Body.Close()

  var r Response
  err = json.NewDecoder(resp.Body).Decode(&r)
  if err != nil {
          panic(err)
  }
  fmt.Printf("r.Time.Updated: %s\n", r.Time.Updated)
  fmt.Printf("r.Time.UpdatedISO: %s\n", r.Time.UpdatedISO)
  fmt.Printf("r.Time.Updateduk: %s\n", r.Time.Updateduk)
  fmt.Printf("r.ChartName: %s\n", r.ChartName)
  fmt.Printf("r.Disclaimer: %s\n", r.Disclaimer)
  fmt.Printf("r.Bpi.USD: %s\n", r.Bpi.USD)
  fmt.Printf("r.Bpi.GBP: %s\n", r.Bpi.GBP)
  fmt.Printf("r.Bpi.EUR: %s\n", r.Bpi.EUR)
  
}