Use of JSON in Golang

This is a creation in Article, where the information may have evolved or changed.

Using JSON in Golang, you often use two of functions

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

1 deserializing JSON into a struct object

2 deserializing JSON into map

3 deserialization of JSON into slice

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

1 serializing a struct object into JSON

2 serializing a map into JSON

3 serializing the slice into JSON

Package Main

Import (

"FMT"

"Encoding/json"

)

Type User struct {

Username string

Password string

Friendname []string

}

Func Main () {

user:=user{}

User. Username= "Tom"

User. Password= "123456"

User. friendname=[]string{"Li", "Fei"}

       // will be struct turn into JSON String, Note: The first letter of a field in a struct must be capitalized, otherwise it cannot be resolved

If Userjson,err:=json. Marshal (user); err==nil{

Fmt. Println (String (Userjson))// print Result:{"Username": "Tom", "Password": "123456", "Friendname": ["Li", "Fei"]}

}

turn slice into a json string

arr:=[]string{"Apple", "Orange", "Banana"}

If Arrjson,err:=json. Marshal (arr); err==nil{

Fmt. Println (String (Arrjson))// print Result:["Apple", "Orange", "Banana"]

}

Turn map into a json string

m:=map[string]string{" Zhejiang ": " Hangzhou ", " Hunan ": " Changsha "}

If Mjson,err:=json. Marshal (m); err==nil{

Fmt. Println (String (Mjson))//print Result: {" zhejiang ": " Hangzhou ", " Hunan ": " Changsha "}

}

JSON into a struct

Jsonstr:= ' {"Username": "Tom", "Password": "123456", "Friendname": ["Li", "Fei"]} '

var Userjson User

If Err:=json. Unmarshal ([]byte (JSONSTR), &userjson); err==nil{

Fmt. PRINTLN (Userjson)// print Result:{Tom 123456 [Li Fei]}

}

JSON turns into slice

Jsonfruit:= ' ["Apple", "Orange", "Banana"] '

var arrfruit []string

If Err:=json. Unmarshal ([]byte (Jsonfruit), &arrfruit); err==nil{

Fmt. PRINTLN (arrfruit)// print Result:[Apple Orange Banana]

}

JSON turns into a map

Jsoncity:= ' {" zhejiang ": " Hangzhou ", " Hunan ": " Changsha "} '

var mapcity map[string]string

If Err:=json. Unmarshal ([]byte (jsoncity), &mapcity); err==nil{

Fmt. PRINTLN (mapcity)// print Result: map[Zhejiang: Hangzhou Hunan: Changsha]

}

}