The ninth video in my Exploring MoreLINQ series looks at the
FillBackward extension methods. These ones allow you to replace "missing" values in the incoming sequence with replacements from elsewhere in the sequence, something that would be tricky to achieve without an extension method like this.
null can be replaced with either the previous non-null value using
FillForward or the next non-null value using
FillBackward. And you can control what is considered a missing value as well, so it doesn't have to be just nulls that get replaced.
You can find all videos in this series here.