从服务器发送JSON需要两次JSON.parse

Question

For some reason I have to call JSON.parse twice to create an object in JavaScript. I'm generating JSON from a Go (Golang) server.

This is the JavaScript code I'm using.

ws.onmessage = function(e) {
    console.log(e.data);
    console.log(JSON.parse(e.data));
    console.log(JSON.parse(JSON.parse(e.data)));
};

And this is what I saw in Chrome's console.

"{\"hello\":\"world\"}"
{"hello":"world"}
Object {hello: "world"}

This is how I'm generating JSON on the server side. I suspect my server code is wrong.

var jsonBuffer bytes.Buffer

jsonBuffer.WriteString("{")
for key, value := range mydict {
    jsonBuffer.WriteString(`"` + key `":"` + value + `"`)
}
jsonBuffer.WriteString("}")

return jsonBuffer.String()

This is a simplification of what I'm working on. In reality, mydict is defined as map[string]mystruct.

mystruct is something like this:

type mystruct struct {
    Foo int
    Bar float64
}

Answer 1

Why are you building the json response by hand? I would suggest to use the json package. Your code would look something like this

package main

import (
    "fmt"
    "encoding/json"
)

type Mystruct struct {
    Foo int
    Bar float64
}

func main() {
    m := Mystruct{1,100}
    j, _ := json.Marshal(m)
    fmt.Print(string(j))
}