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The nullable type is not a nullable type?
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The nullable type is not a nullable type?
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I was doing some testing with nullable types, and it didn't work quite as I expected:
int? testInt = 0;
Type nullableType = typeof(int?);
Assert.AreEqual(nullableType, testInt.GetType()); // not the same type
This doesn't work either:
DateTime? test = new DateTime(434523452345);
Assert.IsTrue(test.GetType() == typeof(Nullable)); //FAIL
DateTime? test = new DateTime(434523452345);
Assert.IsTrue(test.GetType() == typeof(Nullable<>)); //STILL FAIL
My question is why does testInt.GetType() return int, and typeof(int?) return the true nullable type?
According to the MSDN :
Calling GetType on a Nullable type causes a boxing operation to be performed when the type is implicitly converted to Object. Therefore GetType always returns a Type object that represents the underlying type, not the Nullable type.
When you box a nullable object, only the underlying type is boxed.
Again, from MSDN :
Boxing a non-null nullable value type boxes the value type itself, not the System.Nullable that wraps the value type.
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