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

type ColorGroup struct { 
 ID  int 
 Name string 
 Colors []string 
} 
group := ColorGroup{ 
 ID:  1, 
 Name: "Reds", 
 Colors: []string{"Crimson", "Red", "Ruby", "Maroon"}, 
} 
b, err := json.Marshal(group) 
if err != nil { 
 fmt.Println("error:", err) 
} 
os.Stdout.Write(b) 
Output: 
{"ID":1,"Name":"Reds","Colors":["Crimson","Red","Ruby","Maroon"]} 

func Unmarshal(data []byte, v interface{}) error

var jsonBlob = []byte(`[ 
 {"Name": "Platypus", "Order": "Monotremata"}, 
 {"Name": "Quoll", "Order": "Dasyuromorphia"} 
]`) 
type Animal struct { 
 Name string 
 Order string 
} 
var animals []Animal 
err := json.Unmarshal(jsonBlob, &animals) 
if err != nil { 
 fmt.Println("error:", err) 
} 
fmt.Printf("%+v", animals) 
Output: 
[{Name:Platypus Order:Monotremata} {Name:Quoll Order:Dasyuromorphia}]

type Message struct { 
 Name string 
 Body string 
 Time int64 
 inner string 
} 
var m = Message{ 
 Name: "Alice", 
 Body: "Hello", 
 Time: 1294706395881547000, 
 inner: "ok", 
} 
b := []byte(`{"nAmE":"Bob","Food":"Pickle", "inner":"changed"}`) 
err := json.Unmarshal(b, &m) 
if err != nil { 
 fmt.Printf(err.Error()) 
 return 
} 
fmt.Printf("%v", m) 
Output: 
{Bob Hello 1294706395881547000 ok} 

type Message struct { 
 Name string `json:"msg_name"`  // 对应JSON的msg_name 
 Body string `json:"body,omitempty"` // 如果为空置则忽略字段 
 Time int64 `json:"-"`    // 直接忽略字段 
} 
var m = Message{ 
 Name: "Alice", 
 Body: "", 
 Time: 1294706395881547000, 
} 
data, err := json.Marshal(m) 
if err != nil { 
 fmt.Printf(err.Error()) 
 return 
} 
fmt.Println(string(data)) 
Output: 
{"msg_name":"Alice"} 

type Command struct { 
 ID int 
 Cmd string 
 Args *json.RawMessage 
}

JSON的boolean 转换为bool
JSON的数值 转换为float64
JSON的字符串 转换为string
JSON的Array 转换为[]interface{}
JSON的Object 转换为map[string]interface{}

type Marshaler interface { 
 MarshalJSON() ([]byte, error) 
} 
type Unmarshaler interface { 
 UnmarshalJSON([]byte) error 
}