how to get only day number from date in flutter - flutter

Question

I am trying to get day from date, and date comes from the api response, api response look like this
"data": [
{
_id: 6116c2e12760f71630342604,
username: 'abc',
Date: '2021-08-13',
},
{
_id: 6119ba9162069c32ccdf11c3,
username: 'acv',
Date: '2021-08-15',
}
]
i am trying to do it like this
date=Response.data['data']['Date']); //if i get date here 2021-08-15
day=date.split('-') //then will split it [2021,08,05]
day=date[2] //and then will get the day 05
but it is not working, it sends this error
type 'String' is not a subtype of type 'int' of 'index'
when i print this line day=Response.data['data']['Date']); it send same error, it is not getting date, but when i print onResponse.data it prints the api response.
please help how to do this

Answer 1

If your date String is in standard ISO format, simply use DateTime.parse then you can get the day easily, it would also allow you to check that the date is valid (parse will fail if date is not valid, see documentation):
String dateStr = Response.data['data']['Date']);
DateTime dateObj = DateTime.parse(dateStr);
print(dateObj.day);
If this is a custom format, you could use DateFormat from intl package (documentation):
String dateStr = Response.data['data']['Date']);
DateTime dateObj = DateFormat('yyyy-MM-dd').parse(dateStr);
print(dateObj.day);

Answer 2

you should use date.split("-").last and actually your index is wrong it should be day=date[2]

Answer 3

Let's try or you will use day[2]
day=Response.data['data']['Date']); //if i get date here 2021-08-15
day=date?.split('-').last; //then will split [05]
print(day) //and then will get the day 05