Use of C# var for implicit typing of System.Data.Datarow

Question

foreach (var row in table.Rows)
{
     DoSomethingWith(row);
}

Assuming that I\'m working with a standard System.Data.DataTable (which has

Answer 1

That's because Rows is DataRowCollection, which in turn is IEnumerable and not IEnumerable<DataRow>, which means that type inferred will be object.

When you explicitly state type in foreach, you instruct c# to add cast to each call, which is why it works.

Answer 2

An implicit cast happens. Also note that an InvalidCastException can be thrown if the cast isn't possible.