What does a question mark mean in C# code?

2018-06-02 11:49:45

This question already has an answer here:

What does the question mark in member access mean in C#? 2 answers

What do two question marks together mean in C#? 16 answers

What is the purpose of a question mark after a type (for example: int? myVariable)? 8 answers

Benefits of using the conditional ?: (ternary) operator 16 answers

Question marks have different meaning in C# depending on the context.

The Null-Conditional Operator (MSDN, What does the question mark in member access mean in C#?)

Console.Write(myObject?.Items?[0].ToString());

The Conditional Operator/Ternary Operator (MSDN, Benefits of using the conditional ?: (ternary) operator)

return isTrue ? "Valid" : "Lie";

The Null Coalescing Operator (MSDN, What do two question marks together mean in C#?)

return myObject ?? yourObject;

Nullable Types (MSDN, What is the purpose of a question mark after a type (for example: int? myVariable)?)

int? universalAnswer = 42;

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