Null-coalescing operator (??)
The ?? operator is called the null-coalescing operator. It returns the left-hand operand if the operand is not null; otherwise it returns the right hand operand.
myNewValue = myValue ?? new MyValue();
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Ternary operator (?:)
The conditional operator (?:) returns one of two values depending on the value of a Boolean expression.
condition ? first_expression : second_expression;
The condition must evaluate to true or false. If condition is true, first_expression is evaluated and becomes the result. If condition is false, second_expression is evaluated and becomes the result.
classify = (input > 0) ? "positive" : "negative";
Source: https://msdn.microsoft.com/en-us/library/ty67wk28.aspx
