C# List<string[]> to List<object[]> Conversion

Question

All, have I gone mental (this is not the question). I want to convert List<string[]> to List<object[]>

List<string[]> parameters = GetParameters(tmpConn, name);
List<object[]> objParams = parameters.OfType<object[]>();

this is not working, but unless I have forgotten something a conversion using this method should be possible (no Lambdas needed)?

Thanks for your time.

Answer 1

You want to use something like:

List<object[]> objParams = parameters.OfType<object[]>().ToList();

or in C# 4.0, just

List<object[]> objParams = parameters.ToList<object[]>();

or

List<object[]> objParams = parameters.ConvertAll(s => (object[])s);

Answer 2

Because of array covariance, in .NET 4.0, you can just do:

// Works because:
// a) In .NET, a string[] is an object[]
// b) In .NET 4.0, an IEnumerable<Derived> is an IEnumerable<Base>              
var result = parameters.ToList<object[]>();

But note that you wouldn't be able to mutate those arrays with anything other than strings (since array covariance isn't truly safe).

If you want truly flexible writable object arrays, you can do:

var result = parameters.Select(array => array.ToArray<object>())
                       .ToList();

(or)

var result = parameters.ConvertAll(array => array.ToArray<object>());

Then you could replace the elements of each inner array with instances of pretty much any type you please.