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VB.NET null coalescing operator? [duplicate]

This question already has answers here: 开发者_运维技巧 Coalesce operator and Conditional operator in VB.NET [duplicate] (4 answers) Closed 2 years ago.

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Coalesce operator and Conditional operator in VB.NET

Is there a VB.NET equivalent for C#'s ?? operator?

Is there a built-in VB.NET equivalent to the C# null coalescing operator?


Yes, there is, a long as you're using VB 9 or later (included with Visual Studio 2008).

You can use the version of the If operator overloaded to accept only two arguments:

Dim myVar? As Integer = Nothing
Console.WriteLine(If(myVar, 7))

More information can be found here in a blog post by the VB.NET team.

(Yes, this is an operator, even though it looks like a function. It will compile down to the same IL as the "proper" null-coalescing operator in C#.)

Example

Dim b As Boolean?
Console.WriteLine("{0}.", If(b, "this is expected when b is nothing"))
'output: this is expected when b is nothing.

b = False
Console.WriteLine("{0}.", If(b, "this is unexpected when b is false"))
'output: False.

b = True
Console.WriteLine("{0}.", If(b, "this is unexpected when b is true"))
'output: True.


According to this question it would seem the answer is If()


No. Use GetValueOrDefault; that's why it's there!


I don't believe that there is a built in VB.Net equivalent, but here's an answer: null coalesce operator in VB.Net(8)

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