C# Nullable<DateTime> to string

Question

I have a DateTime? variable, sometimes the value is null, how can I return an empty string "" when the value is null or the DateTime value when not null?

Answer 1

            DateTime? MyNullableDT;
            ....
            if (MyNullableDT.HasValue)
            {
                return MyNullableDT.Value.ToString();
            }
            return "";

Answer 2

string date = myVariable.HasValue ? myVariable.Value.ToString() : string.Empty;

Answer 3

DateTime? d;
// stuff manipulating d;
return d != null ? d.Value.ToString() : String.Empty;

Answer 4

    if (aDate.HasValue)
        return aDate;
    else
        return string.Empty;

Answer 5

DateTime d?;
string s = d.HasValue ? d.ToString() : string.Empty;

Answer 6

You could write an extension method

public static string ToStringSafe(this DateTime? t) {
  return t.HasValue ? t.Value.ToString() : String.Empty;
}

...
var str = myVariable.ToStringSafe();

Answer 7

Actually, this is the default behaviour for Nullable types, that without a value they return nothing:

public class Test {
    public static void Main() {
        System.DateTime? dt = null;
        System.Console.WriteLine("<{0}>", dt.ToString());
        dt = System.DateTime.Now;
        System.Console.WriteLine("<{0}>", dt.ToString());
    }
}

this yields

<>
<2009-09-18 19:16:09>

Answer 8

string date = myVariable.HasValue ? myVariable.ToString() : string.Empty;

Answer 9

Though many of these answers are correct, all of them are needlessly complex. The result of calling ToString on a nullable DateTime is already an empty string if the value is logically null. Just call ToString on your value; it will do exactly what you want.

Answer 10

The shortest possible way is to use this:

Convert.ToString(myVariable);

If it receives null, the result will be an empty string. Otherwise, it will call DateTime.ToString().

Answer 11

Calling .ToString() returns an empty string for a null value.

Answer 12

Always try to avoid using Convert.Toxxxxx. The overhead is massive, especialy when processing a large number of "records".

Barry