C# equivalent of the IsNull() function in SQL Server

Question

In SQL Server you can use the IsNull() function to check if a value is null, and if it is, return another value. Now I am wondering if there is anything similar

Answer 1

public static T isNull(this T v1, T defaultValue)
{
    return v1 == null ? defaultValue : v1;
}

myValue.isNull(new MyValue())