Check if Nullable Guid is empty in c

Question

Quoting from an answer from this question      Guid is a value type  so a variable of type Guid can t be null to   start with    What then if I see this   public Nullable lt System Guid gt  SomeProperty   get  set      how should I check if this is null  Like this    SomeProperty    null    or like this    SomeProperty    Guid Empty

User · Answer

Beginning with C  7 1  you can use default literal to produce the default value of a type when the compiler can infer the expression type   Console Writeline default Guid            ouptut  00000000-0000-0000-0000-000000000000  Console WriteLine default int        output  0  Console WriteLine default object  is null       output  True   https   docs microsoft com en-us dotnet csharp language-reference operators default

User · Answer

If you want be sure you need to check both  SomeProperty    null    SomeProperty    Guid Empty   Because it can be null  Nullable  and it can be an empty GUID something like this  00000000-0000-0000-0000-000000000000

User · Answer

You should use the HasValue property   SomeProperty HasValue  For example   if  SomeProperty HasValue           Do Something   else          Do Something Else     FYI  public Nullable lt System Guid gt  SomeProperty   get  set      is equivalent to   public System Guid  SomeProperty   get  set      The MSDN Reference  http   msdn microsoft com en-us library sksw8094 aspx

User · Answer

Note that HasValue will return true for an empty Guid   bool validGuid   SomeProperty HasValue  amp  amp  SomeProperty    Guid Empty

User · Answer

SomeProperty HasValue I think it s what you re looking for   EDIT   btw  you can write System Guid  instead of Nullable lt System Guid gt

User · Answer

Check Nullable lt T gt  HasValue  if  SomeProperty HasValue   SomeProperty Value    Guid Empty       not valid GUID   else      Valid GUID

[c#] Check if Nullable Guid is empty in c#

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