notesJSON

##JSON Marshal and Unmarshal

The marshal and Unmarshal method returned in Bytes format, but we can change these data to strings/JSON in Go.

'encoding/json' package for json related operation in golang.
Marshal use to convert Go object into JSON and Unmarshal is vice versa

##1) Marshalling (struct data into json)

json.Marshal() method converts Struct into Byte data
ip :- object as a param 
op :- Bytes code

type Employee struct {
    Name string
    Age int
    salary int
}

1 emp_obj := Employee{Name:"Rachel", Age:24, Salary :344444}
2 emp, _ := json.Marshal(emp_obj)
3 fmt.Println(string(emp))

Line 1: Creating object using Employee Struct.
Line 2: Convert Struct Object into Byte data.
Line 3: Convert Byte data into json string to display data.

The Output :
{"Name":"Rachel","Age":24,"Salary":344444}

##2) Unmarshalling (json(Byte data) into Struct Object)

ip:- json byte data as a param 
op:- struct object

The string keys in the JSON are matched to the field names in the structs.

e.g. 
type Response struct {
    Name string `json:"name"`
    Age int `json:"age"`
    Salary int `json:"salary"`
}


1 bytes := []byte(str_emp)
2 var res Response
3 json.Unmarshal(bytes, &res)
4 fmt.Println(res.Name)

Line 1: Creating json string into byte code.
Line 2: Create empty Response struct and assign res variable.
Line 3: Unmarshal by passing a pointer to an empty structs.
Line 3: Print the Struct Name value.

Reference : - https://www.restapiexample.com/golang-tutorial/marshal-and-unmarshal-of-struct-data-using-golang/