Question

Is there a way to “convert” (return) an IEnumerable list of, e.g., strings to an IEnumerable list of a different type when that different type accepts the former type in its constructor?

For example, the DataTable.Columns.AddRange() method accepts only lists of columns. Is there a way to return a DataColumn list by offering a string list using LINQ or some sort of aggregate function? I imagine the code would roughly do the following, but in one line:

var columnList = new List<DataColumn>();
foreach (var item in myStringList)
{
    columnList.Add(item);
}
return columnList;

Likewise, is there an aggregate method that will take a list and run each of its members against a specific method? For example, I am looking for a one line way to perform the following similar foreach loop:

foreach (var item in myStringList)
{
    myDataTable.Columns.Add(item);
}

Obviously, I am looking for generic answers that are not actually dependent on data columns or strings.

Answer 1

You can write

var newList = list.ConvertAll(x => new Something(x));
list.ForEach(x => DoSomething(x));

These methods are defined by th List<T> class.

If you have an arbitrary IEnumerable<T>, you can use LINQ:

var newEnumerable = enumerable.Select(x => new Something(x));