go json与map相互转换

#函数定义位于GOROOT or GOPATH的/src/encoding/json/encode.go 中
 
func Marshal(v interface{}) ([]byte, error) {
        e := newEncodeState()
 
        err := e.marshal(v, encOpts{escapeHTML: true})
        if err != nil {
                return nil, err
        }
        buf := append([]byte(nil), e.Bytes()...)
 
        encodeStatePool.Put(e)
 
        return buf, nil
}

#函数定义位于GOROOT or GOPATH的/src/encoding/json/decode.go 中
 
func Unmarshal(data []byte, v interface{}) error {
        // Check for well-formedness.
        // Avoids filling out half a data structure
        // before discovering a JSON syntax error.
        var d decodeState
        err := checkValid(data, &d.scan)
        if err != nil {
                return err
        }
 
        d.init(data)
        return d.unmarshal(v)
}
 
 
#输入的数据类型是[]byte,string类型的话要转成[]byte.
str1 := "hello"
data := []byte(str1)  // 将字符串转为[]byte类型

// 当前程序的包名
package main
 
// 导入其它的包
import (
    "encoding/json"
    "fmt"
)
 
func main() {
    map2json2map()
}
 
func map2json2map() {
 
    map1 := make(map[string]interface{})
    map1["1"] = "hello"
    map1["2"] = "world"
    //return []byte
    str, err := json.Marshal(map1)
 
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println("map to json", string(str))
 
    //json([]byte) to map
    map2 := make(map[string]interface{})
    err = json.Unmarshal(str, &map2)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println("json to map ", map2)
    fmt.Println("The value of key1 is", map2["1"])
}