NullableTGetValueOrDefault

NullableTGetValueOrDefault is a method in C# that provides a convenient way to retrieve the value of a nullable type or a default value if the nullable type is null. A nullable type, denoted by a question mark after the type name (e.g., int?, bool?, DateTime?), can either hold a value of its underlying type or be null.

The GetValueOrDefault method is part of the Nullable<T> struct. When called on a nullable type instance, it checks if the instance has a value. If it does, it returns that value. If the instance is null, it returns the default value for the underlying type. For numeric types, the default value is 0. For boolean types, it's false. For reference types, it's null.

There are two overloads for this method. The parameterless overload returns the default value of the underlying type. The overload that accepts a parameter allows you to specify a custom default value to be returned if the nullable type is null. This overload is particularly useful when you need a specific value other than the type's default. For instance, if you have a nullable integer `int? count` and want to treat a null count as -1, you can use `count.GetValueOrDefault(-1)`. This method simplifies null-checking logic and makes code more readable by reducing the need for explicit if statements to handle null cases.