Brother Lian Blockchain technology training share go language processing JSON array

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Today encountered an interface need to work with a JSON map type array, the idea is to use the array in the Simple-json to read arrays, and then iterate through the array to fetch each map, and then read the corresponding values, in the subsequent operation, seemingly very simple work, but encountered a trap.

The JSON format is similar to the bottom:

{"Code": 0

, "request_id": xxxx

, "code_msg": ""

, "body": [{

"device_id": "XXXX"

, "Device_hid": "XXXX"

}]

, "Count": 0}

Soon according to the above ideas to write the code, but it happened, compile, but look at the code logic there is no problem, where is the problem?

The original is interface{} The array method returned is a interface{} type, we are all in Golang interface is a universal recipient can save any type of argument, but ignore the point, it is not to take for granted when any type to use, Be sure to judge the interface type before using it. I ignored this at first, and took the interface variable for granted to cause the error.

Here's a small example.

Package Main

Import (

"Encoding/json"

"FMT"

"Github.com/bitly/go-simplejson"

)

Func Main () {

Patchwork JSON body as map array

var rbody []map[string]interface{}

T: = Make (map[string]interface{})

t["device_id"] = "DDDDDD"

t["Device_hid"] = "DDDDDDD"

Rbody = append (rbody, T)

T1: = Make (map[string]interface{})

t1["device_id"] = "AAAAA"

t1["Device_hid"] = "AAAAA"

Rbody = Append (rbody, T1)

Cnnjson: = Make (map[string]interface{})

cnnjson["code"] = 0

cnnjson["request_id"] = 123

cnnjson["code_msg"] = ""

cnnjson["Body"] = Rbody

cnnjson["page"] = 0

cnnjson["page_size"] = 0

B, _: = json. Marshal (Cnnjson)

CNNN: = string (b)

Fmt. Println ("cnnn:%s", cnnn)

Cn_json, _: = Simplejson. Newjson ([]byte (CNNN))

Cn_body, _: = Cn_json. Get ("Body"). Array ()

For _, Di: = Range Cn_body {

This is where the di is judged by type.

Newdi, _: = Di. (map[string]interface{})

device_id: = newdi["device_id"]

Device_hid: = newdi["Device_hid"]

Fmt. Println (Device_hid, device_id)

}

}

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