package main

import (
	"fmt"
	"strings"
	"net/url"
)

func main() {
	q := url.Values{}
	q.Add("b", "testing")
	q.Add("a", "hello world")

	// url.Values will sort keys(alphabet asc)
	// and encode ' '(blank) to '+', SHOULD replace to '%20'
	s := strings.ReplaceAll(q.Encode(), "+", "%20")
	fmt.Println(s)
}