Question

Is there an easier way to achieve the following?

var obj = from row in table.AsEnumerable()           select row['DOUBLEVALUE'];  double[] a = Array.ConvertAll<object, double>(obj.ToArray(), o => (double)o); 

I’m extracting a column from a DataTable and storing the column in an array of doubles.

Assume that table is a DataTable containing a column called ‘DOUBLEVALUE’ of type typeof(Double).

Answer 1

var obj = (from row in table.AsEnumerable()       select row.Field<double>('DOUBLEVALUE')).ToArray(); 

The .ToArray() bit is optional, of course; without the ToArray(), you’ll get an enumerable sequence of doubles instead of an array – it depends whether you need to read it once or twice. If you have nulls in the data, use <double?> instead.

(note that this needs a reference to System.Data.DataSetExtensions.dll, and a ‘using System.Data;’ statement – this brings the .Field<T>(...) extension methods into play)