How to check if a DateTime field is not null or empty? [duplicate]

Question

I am very new in C# and I have a doubt.

In an application on which I am working I found something like it in the code:

if (!String.IsNullOrEmpty(u.nome)) 

This code simply check if the nome field of the u object is not an empty\null string.

Ok this is very clear for me, but what can I do to check it if a field is not a string but is DateTime object?

Answer 1

If you declare a DateTime, then the default value is DateTime.MinValue, and hence you have to check it like this:

DateTime dat = new DateTime();   if (dat==DateTime.MinValue)  {      //unassigned  } 

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If the DateTime is nullable, well that's a different story:

 DateTime? dat = null;   if (!dat.HasValue)  {      //unassigned  }