test.go

package main

import (
  "encoding/json"
  "fmt"
  "io/ioutil"
  "log"
  "net/http"
  "time"
)

type jokejson struct {
  Joke string `json:"joke"`
}

func main() {
  url := "https://sv443.net/jokeapi/v2/joke/Programming?type=single"

  c := http.Client{
    Timeout: time.Second * 30,
  }

  req, err := http.NewRequest(http.MethodGet, url, nil)
  if err != nil {
    log.Fatal(err)
  }

  res, getErr := c.Do(req)
  if getErr != nil {
    log.Fatal(getErr)
  }

  if res.Body != nil {
    defer res.Body.Close()
  }

  body, readErr := ioutil.ReadAll(res.Body)
  if readErr != nil {
    log.Fatal(readErr)
  }

  j := jokejson{}
  jsonErr := json.Unmarshal(body, &j)
  if jsonErr != nil {
    log.Fatal(jsonErr)
  }

  fmt.Printf(j.Joke)
}