.map is not returning json object to console

i am new to ionic 3 and i am working on fetching data from my own rails api.
i am getting response on the console but not getting [object] in console.
this is my return code

return this.http.get(this.url)
.do((res: Response) => console.log(res))
.map((res: Response) => res.json())

my json file look like this
[
{
“id”: 1,
“firstname”: “aditya”,
“lastname”: null,
“shirtSize”: null,
“vegetarian”: null,
“created_at”: “2017-10-24T15:13:54.807Z”,
“updated_at”: “2017-10-24T15:13:54.807Z”
},
{
“id”: 2,
“firstname”: “aditya”,
“lastname”: “pandit”,
“shirtSize”: “M”,
“vegetarian”: true,
“created_at”: “2017-10-24T15:14:28.080Z”,
“updated_at”: “2017-10-24T15:14:28.080Z”
},
{
“id”: 3,
“firstname”: “ravi”,
“lastname”: “singh”,
“shirtSize”: “M”,
“vegetarian”: null,
“created_at”: “2017-10-24T15:15:48.386Z”,
“updated_at”: “2017-10-24T15:15:48.386Z”
},
{
“id”: 5,
“firstname”: “jai”,
“lastname”: “sharma”,
“shirtSize”: “M”,
“vegetarian”: true,
“created_at”: “2017-10-26T11:12:01.449Z”,
“updated_at”: “2017-10-26T11:12:01.449Z”
},
{
“id”: 6,
“firstname”: “nikita”,
“lastname”: “pandey”,
“shirtSize”: “M”,
“vegetarian”: true,
“created_at”: “2017-10-26T13:14:37.462Z”,
“updated_at”: “2017-10-26T13:14:37.462Z”
},
{
“id”: 7,
“firstname”: “anand”,
“lastname”: “kumar”,
“shirtSize”: “L”,
“vegetarian”: true,
“created_at”: “2017-11-13T12:53:37.544Z”,
“updated_at”: “2017-11-13T12:53:37.544Z”
}
]

Shouldn’t the .do() come after the .map() if you want it to be JSON?