Question

I have a pretty simple structure that looks something like this:

var list = new List<CategoryInTimeItem>
        {
            new CategoryInTimeItem { Name = "Food", Year = 2012, Month = 1, Amount = 100 },
            new CategoryInTimeItem { Name = "Food", Year = 2012, Month = 2, Amount = 110 },
            new CategoryInTimeItem { Name = "Food", Year = 2012, Month = 3, Amount = 130 },
            new CategoryInTimeItem { Name = "Food", Year = 2012, Month = 4, Amount = 130 },
            new CategoryInTimeItem { Name = "Transport", Year = 2012, Month = 1, Amount = 1000 },
            new CategoryInTimeItem { Name = "Transport", Year = 2012, Month = 2, Amount = 1101 },
            new CategoryInTimeItem { Name = "Transport", Year = 2012, Month = 3, Amount = 1301 },
            new CategoryInTimeItem { Name = "Transport", Year = 2012, Month = 4, Amount = 1301 }
        };

I want to reshape this structure so that when it get’s serialized to json the result should look like this, one array for each name:

[
[["2012-1", 100], ["2012-2", 110], ["2012-3", 130], ["2012-4", 130]],
[["2012-1", 1000], ["2012-2", 1101], ["2012-3", 1301], ["2012-4", 1301]]
]

My linq query looks like this:

   result.Values = 
                from d in list
                orderby d.Name , d.Year , d.Month
                group d by d.Name
                into grp
                select new[]
                {
                    grp.Select(y => new object[] {y.DateName, y.Amount})
                };

This almost works, however I get an extra “level” of arrays, so when serialized to json the result looks like this:

[
[[["2012-1", 100], ["2012-2", 110], ["2012-3", 130], ["2012-4", 130]]],
[[["2012-1", 1000], ["2012-2", 1101], ["2012-3", 1301], ["2012-4", 1301]]]
]

What am I doing wrong here?

Answer 1

You’ve almost been there, just instead of

from d in list
...
select new[]
{
    grp.Select(y => new object[] {y.DateName, y.Amount})
}

simply:

from d in list
...
select grp.Select(y => new object[] {y.DateName, y.Amount}).ToList()

You just added an unnecessary level of array at the end.