Null-Coalescing Operator ( ?? )
If tempFileName is not null, fileName = tempFileName, else fileName = “Untitled“।
This can now be abbreviated as follows using the Null-Coalescing Operator:
string fileName = tempFileName ?? “Untitled”;
The logic is the same। If tempFileName is not null, fileName = tempFileName, else fileName = “Untitled“.
The Null-Coalescing Operator comes up a lot with nullable types, particular when converting from a nullable type to its value type:
int? count = null;
int amount = count ?? default(int);
Since count is null, amount will now be the default value of an integer type ( zero )।
These Conditional and Null-Coalescing Operators aren’t the most self-describing operators 
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but I do love programming in C#!
