Lambda Expressions in Excel VBA

@TMS, I'm not quite sure how to answer that question. The short answer would be that as far as I know Excel VBA doesn't nativly support Lambda Expressions, so this would be an extension to Excel VBA's functionality.

Re-writing the example subs: ToProperSelection, ToUpperSelection, ToLowerSelection, TrimSelection and ScrubSelection, without the Lambda would mean making a copy of the optimized loop body found in LambdaSelectionByVal into each of these functions individually. So essentually Lambda Expressions add a layer of polymorphism to the code so that you can write and maintain one sub/function (in this case an optimized itterator over selected cells) that will perform any sub/function that you hand to it. In other words writing your own sub to apply FunctionX to the currently selected cells that have data is now just as easy as a one-liner:

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The seccond Lambda based example sub LambdaRangeByVal is maybe a little more obtuse. In my past experience with excel I've found that when I fill a range of cells with a function =MyVBAFunction(B1,C1) that this works fine untill you start trying to do ranges of somewhere around 100,000 cells or more, then the run time of the MyVBAFunction starts to weigh heavily into the calculation time on the speadsheet and even causes Excel to crash from time to time. So I wrote this Lambda based sub to apply <Insert your favorite MyVBAFunction of one or two parameters here> across a range of three columns {result column, B column, C column} row by row storing only the result along the way.

Even though the two Lambda based subs I had were designed around the itterator concept you needn't stop there, you could just as easily develop a Lambda based recursive sub that updates the Lambda function on the fly (I'm thinking AI and/or FSM here).

So I suppose the longer answer is: like subs, function calls, and class modules it's just another tool in the programmer's tool box.