Where is guid null defined

I tried your suggestion and it did not work. I guess the reason is I am trying to set a regular. This may work with the database table but not with a class instance. When I tried, it said "Cannot convert Sourcetype 'object' to targettype 'system. You'd think that the compiler would be smart enough to be able to implicitly do that cast between Guid? Perhaps when they added those new nullable types to the language, they forgot to add the capability to implicitly cast to the compiler.

Learn More. Ask a question. Quick access. Search related threads. Remove From My Forums. Answered by:. I'll create a parsing method quicker than our discussion would take. If we need to store nulls in value types the normal solution is to use Nullable or as a shorthand use the?

This will also work with standard serializers so the value will be either missing or have the literal null value.

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Learn more. What should a rest api return for an empty guid? Ask Question. Asked 4 years, 4 months ago. Active 3 years, 2 months ago. Viewed 7k times. Empty But the iOS developer talks about creating a parsing method so not build in I guess. I know what I like to do but what do you think I should do? Improve this question. Sturla Sturla 1 1 silver badge 3 3 bronze badges. Firstly, what's he do if it's not an empty GUID?

Also, why does he need a parse method for empty but not a non-empty GUID? Can't he just do an equality check against the string ""? Empty Guid is different than non-existing Guid. By all means the convention of empty on.

Net is Instead of trying to define what's empty and what's not, you have to define the meaning of having and not having a Guid, use a convention that would be easy for all platforms web, IOS, Android, etc Machado well is it a. It only have missing variables maybe technically a null , maybe doesn't exist at all and those that are there.

I don't really get why is that needed in your case. Can you show a simplified example of the situation? How to set null to a GUID property. Asked 4 Months ago Answers: 5 Viewed 50 times.

Any help please! When you box a nullable object, only the underlying type is boxed. IsFocused textBox. If you try it, it will not compile. The reason once more is that struct is not a primitive type. For a list of all primitive types in. I'm not saying it needs a constant. It needs something that can be decided in compile time.

Empty is a field, so, it's value is not known in compile time only at very beginning of run time. Default parameter value must be known at compile-time, which may be a const value, or something defined using a C feature that makes value known at compile time, like default Guid or new Guid which is decided at compile time for struct s as you cannot modify the struct constructor in code.

While you can provide default or new easily, you cannot provide a const because it's not a primitive type or an enum as explained above. So, again, not saying that optional parameter itself needs a constant, but compiler known value. You need to feed an anonymous function as a parameter instead of a string, the latter method shouldn't even work per the ECMAScript specification but browsers are just lenient.