class People  :   Codable {

    let firstName : String
    let lastName : String

    var fullName : String{
        get{
            return firstName + " " + lastName;
        }
    }
    var age : Int

    init(firstName : String, lastName : String, age : Int){
        self.firstName = firstName
        self.lastName = lastName
        self.age = age

    }

    var description: String {

        return firstName + " " + lastName +  "(age : " + "\(age)" + " )"

            }
}

let p1 = People(firstName: "firstName of P1", lastName: "lastName of P1", age: 10)
let p2 = People(firstName: "firstName of  P2", lastName: "lastName of P2", age: 20)

let peoples = [p1,p2]


// encoding
let encodedPeoples = try? JSONEncoder().encode(peoples)



// decoding
// """ is for multiple line
let jsonString = """
{
    "firstName":"fName",
    "lastName":"lName",
    "age" : 15

}
"""

if let jsonData = jsonString.data(using: .utf8)
{
    let peopleObject = try? JSONDecoder().decode(People.self, from: jsonData)

    if let pObject = peopleObject{
        print( pObject.firstName )
        print( pObject.lastName )
        print( pObject.age )
    }
}