英文:
how to Unmarshal json in golang
问题
我有一个 JSON 数据：
{"code":200,
"msg":"success",
"data":{"url":"https:\/\/mp.weixin.qq.com\/cgi-bin\/showqrcode?ticket=gQHQ7jwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyX3pqS0pMZlA4a1AxbEJkemhvMVoAAgQ5TGNYAwQsAQAA"}}
我定义了一个结构体：
type Result struct {
code int
msg string `json:"msg"`
data map[string]interface{} `json:"data"`
}
对于这段代码：
var res Result
json.Unmarshal(body, &res)
fmt.Println(res)
输出结果是：{0 map[]}
我想要获取 data 中的 url，该如何获取呢？
英文:
I have a json:
{"code":200,
"msg":"success",
"data":{"url":"https:\/\/mp.weixin.qq.com\/cgi-bin\/showqrcode?ticket=gQHQ7jwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyX3pqS0pMZlA4a1AxbEJkemhvMVoAAgQ5TGNYAwQsAQAA"}}
and i define a struct :
type Result struct {
code int
msg string `json:"msg"`
data map[string]interface{} `json:"data"`
}
for this code:
var res Result
json.Unmarshal(body, &res)
fmt.Println(res)
the output is: {0 map[]}
i want to get url in data, how to get it?
答案1
得分: 4
你应该通过将字段（Code、Msg、Data）的首字母大写来导出Result的字段（code、msg、data），以便访问（设置/获取）它们：
package main
import (
"encoding/json"
"fmt"
)
type Result struct {
Code int `json:"code"`
Msg string `json:"msg"`
Data map[string]interface{} `json:"data"`
}
func main() {
str := `{"code":200,"msg":"success","data":{"url":"https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=gQHQ7jwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyX3pqS0pMZlA4a1AxbEJkemhvMVoAAgQ5TGNYAwQsAQAA"}}`
var res Result
err := json.Unmarshal([]byte(str), &res)
fmt.Println(err)
fmt.Println(res)
}
在https://play.golang.org/p/23ah8e_hCa上运行代码。
相关问题：https://stackoverflow.com/questions/24837432/golang-capitals-in-struct-fields
英文:
You should export fields (code, msg, data) for Result by capitalizing the first letter of fields (Code, Msg, Data) to access (set/get) them:
package main
import (
"encoding/json"
"fmt"
)
type Result struct {
Code int `json:"code"`
Msg string `json:"msg"`
Data map[string]interface{} `json:"data"`
}
func main() {
str := `{"code":200,"msg":"success","data":{"url":"https:\/\/mp.weixin.qq.com\/cgi-bin\/showqrcode?ticket=gQHQ7jwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyX3pqS0pMZlA4a1AxbEJkemhvMVoAAgQ5TGNYAwQsAQAA"}}`
var res Result
err := json.Unmarshal([]byte(str), &res)
fmt.Println(err)
fmt.Println(res)
}
Play the code on https://play.golang.org/p/23ah8e_hCa
Related question: https://stackoverflow.com/questions/24837432/golang-capitals-in-struct-fields
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