DateTime?.ToString(format) [duplicate]

Question

Possible Duplicate:
How can I format a nullable DateTime with ToString()?

got issue parsing DateTime? to specific format. Like:

 DateTime t1 = ...;
 string st1 = t1.ToString(format); //<-- works

 DateTime? t1 = ...;
 string st1 = t1.ToString(format); //Dont work.

Theres no overload method for DateTime?

Answer 1

if (t1.HasValue)
    string st1 = t1.Value.ToString(format);

Answer 2

Use Coalesce Operator

DateTime? t1 = ...;

string st1 = t1 ?? t1.Value.ToString(format);