List of values to list of strings

Question

How to convert it:

var values = new List<object> { 1, 5, "eeE", MyEnum.Value };

To

var stringValues = new List<object> { "1", "5", "eeE", MyEnum.Value.ToString() };

But do it in fast way?

Answer 1

here's one approach

//original list
var values = new List<object> { 1, 5, "eeE", Colors.Red };
//List<string>
var stringValues = values.Select(x => x.ToString()).ToList();
//List<object>
var stringValuesAsObjectList = values.Select(x => x.ToString()).ToList<object>();

Answer 2

First, it's not clear whether your question is any different from Convert List(of object) to List(of string); if it is, you should clarify your particular situation.

The straight-forward solution is to use LINQ: var stringValues = values.Select(v => (object) v.ToString()).ToList(); Note the cast to object to match your code above.

It's not clear why you'd want your result to be List<object> instead of List<string>. Also, you should prefer to work with IEnumerable<> instead of converting to a List<>. So the preferred code would be

var stringValues = values.Select(v => v.ToString());

If you're doing this type of thing a lot, you might find an extension method useful

static class ListExtensions
{
   public static IEnumerable<string> AsStrings(this List<object> values)
   {
      return values.Select(v => v.ToString());
   }
}

You would use it like:

var stringValues = values.AsStrings();

Depending on your needs, you may want more a more sophisticated string conversion than Object.ToString(). Convert.ToString() tries to first find IConvertable and IFormattable interfaces before calling ToString().

    var stringValues = values.Select(v => Convert.ToString(v));