Golang basic knowledge of the Encoding/json package

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Golang JSON of basic knowledge

Brief introduction

JSON (JavaScript Object Notation) is a lightweight data interchange format. You can go to json.org to see a clear definition of the JSON standard. The JSON package is the official Go Language pack, followed by an open source implementation of the JSON packages analysis.

Encoding

Func Marshal (v interface{}) ([]byte, error)

Basic type

Bolb, _: = json. Marshal (True) fmt. Println (String (Bolb)) IntB, _: = json. Marshal (1) fmt. Println (String (IntB)) FLTB, _: = json. Marshal (2.34) fmt. Println (String (FLTB))

Output

True
1
2.34
"Gopher"

Serialization of custom types

Type Response1 struct {Page   intfruits []string}//the JSON package can automatically encode your//custom data types. It would only include exported//fields in the encoded output and would by default//use those names as the JSON keys.res1d : = &response1{page:   1,fruits: []string{"Apple", "peach", "pear"}}res1b, _: = json. Marshal (RES1D) fmt. Println (String (res1b))

Only the externally accessible fields can be serialized into JSON.

Data structures that can be rendered in JSON form can be encode:

Because JSON objects only support strings for Key,go map types must be in the form of map[string]t

Channel, complex and function cannot be encode

The data structure of the loop does not support

The pointer is encode by the value pointed to

Decoding

Func unmarshal (data []byte, v interface{}) Errorb: = []byte (' {"Name": "Bob", "Food": "Pickle"} ') var m messageerr: = json. Unmarshal (b, &m)

Deserialization automatically ignores fields that are not externally accessible or missing fields in the structure

Using interface{} to process common JSON

B: = []byte (' {' "Name": "Wednesday", "Age": 6, "parents": ["Gomez", "Morticia"]} ') var f interface{}err: = json. Unmarshal (b, &f) b: = []byte (' {' "Name": "Wednesday", "Age": 6, "parents": ["Gomez", "Morticia"]} ') var f interface{}err: = json. Unmarshal (b, &f) if err! = Nil {panic (err)}m: = f. (map[string]interface{}) for k, V: = range m {Switch VV: = V. (type) {C ASE String:fmt. Println (k, ' is String ', vv) case int:fmt. Println (K, "is Int.", VV) case []INTERFACE{}:FMT. Println (K, "is a array:") for I, U: = Range VV {fmt. Println (i, u)}default:fmt. Println (K, "is of a type I don ' t know how to Handle")}}

Streaming encoders and decoders

Package Mainimport (    "Encoding/json"    "Log" "    OS") Func main () {dec: = json. Newdecoder (OS. Stdin) ENC: = json. Newencoder (OS. Stdout) for {    var v map[string]interface{}    If err: = Dec. Decode (&V); Err! = Nil {        log. PRINTLN (Err)        return    } for    k: = Range v {        if k! = "Name" {            Delete (V, k)}    }    If err: = E nc. Encode (&V); Err! = Nil {        log. PRINTLN (Err)    }}}

See:

http://blog.golang.org/json-and-gohttps://golang.org/pkg/encoding/json/#pkg-examples

Note:

This series is not a chatty Package API guide, only included in the author's view of the most common use, the protest is invalid.