在Golang的一个键中解组多种数据类型

Question

I have JSON key which will have any one the below data.

1.{"value": "ve"}

2.{"value": ["ve","ff"]}

3.{"value": [1,2]}

4.{"value": 3}

How to unmarshal into a golang's struct?

Answer 1

The easiest way is to just use interface{} in your struct. See:

package main

import (
    "encoding/json"
    "fmt"
)

type decoded struct {
    Value interface{}       `json:"value"`
}

func decode(jstr string) {
    var val decoded
    json.Unmarshal([]byte(jstr), &val)
    fmt.Printf("%v
", val.Value)
}

func main() {
    decode(`{"value": "ve"}`)
    decode(`{"value": ["ve","ff"]}`)
    decode(`{"value": [1,2]}`)
    decode(`{"value": 3}`)
}

You'll probably need to combine this with stuff in the reflect package or (as I did above) fmt.Sprintf() or similar to actually get at your data. This is, however, good enough to decode and put in a structure:

$ ./spike 
ve
[ve ff]
[1 2]
3