C# ?? Null Coalescing Operator

A great way in C# to check for null values and handle them in a controlled way is the null coalescing operator ??. It provides a clear way to check whether a value is null, and turn an alternate value if it is.

The coalescing operator checks the value on the left side of the expression to see if it is null. If the value is null it will return an alternate value indicated by the right side of the express. If the value isn’t null, the original value is returned.

string TestVariable = "this is not null";
string TestValue = TestVariable ? "return if null";

In this case the TestValue would contain “This is not null”.

string TestVariable = null;
string TestValue = TestVariable ? "return if null";

In this case, the TestValue would contain “return if null”.