json - How to display a character instead of ascii?

Question

This is my testing code. Just make a simple HTTP server. Then generating a JSON data that it values is "&". But the result is what I don't want. The result is below the code block.

package main

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

func testFunc(w http.ResponseWriter, r *http.Request) {
    data := make(map[string]string)
    data["key"] = "&"
    bytes, err := json.Marshal(data)
    if err != nil {
        fmt.Fprintln(w, "generator json error")
    } else {
        //print console
        fmt.Println(string(bytes))
        fmt.Println("&")
        //print broswer
        fmt.Fprintln(w, string(bytes))
        fmt.Fprintln(w, "&")
    }
}

func main() {
    http.HandleFunc("/", testFunc)
    err := http.ListenAndServe(":9090", nil)
    if err != nil {
        log.Fatal("ListenAndServe", err)
    }

}

result: Chrome browser show:

{"key":"u0026"}
&

Console also show:

{"key":"u0026"}
&

When & not in JSON, browser and console will print &.

Answer 1

Waitting for answers