注意事项
    map记得分配内存
    解析出来的int类型会变成float64类型
    注意判断不为nil后再转换类型

    1. package main
    2. import (
    3.    "fmt"
    4.    "encoding/json"
    5. )
    6. func main() {
    7.    var m map[string]interface{}    //声明变量，不分配内存
    8.    m = make(map[string]interface{}) //必可不少，分配内存
    9.    m["name"] = "simon"
    10.    var age int = 12
    11.    m["age"] = age
    12.    m["addr"] = "China"
    13.    print_map(m)
    14.    fmt.Println()
    15.    data, err:=json.Marshal(m)
    16.    fmt.Println("err:", err)
    17.    fmt.Println(data)
    18.    fmt.Println()
    19.    m1 := make(map[string]interface{})
    20.    err = json.Unmarshal(data, &m1)
    21.    fmt.Println("err:", err)
    22.    fmt.Println(m1)
    23.    print_map(m1)
    24.    fmt.Println()
    25.    if m1["name"]!= nil {
    26.        fmt.Println(m1["name"].(string))
    27.    }
    28.    if m1["type"]!= nil {
    29.        fmt.Println(m1["type"].(string))
    30.    } else {
    31.        fmt.Println("there is not the key of type")
    32.    }
    33. }
    34. //解析 map[string]interface{} 数据格式
    35. func print_map(m map[string]interface{}) {
    36.    for k, v := range m {
    37.        switch value := v.(type) {
    38.        case nil:
    39.            fmt.Println(k, "is nil", "null")
    40.        case string:
    41.            fmt.Println(k, "is string", value)
    42.        case int:
    43.            fmt.Println(k, "is int", value)
    44.        case float64:
    45.            fmt.Println(k, "is float64", value)
    46.        case []interface{}:
    47.            fmt.Println(k, "is an array:")
    48.            for i, u := range value {
    49.                fmt.Println(i, u)
    50.            }
    51.        case map[string]interface{}:
    52.            fmt.Println(k, "is an map:")
    53.            print_map(value)
    54.        default:
    55.            fmt.Println(k, "is unknown type", fmt.Sprintf("%T", v))
    56.        }
    57.    }
    58. }