New functions in excel 2016
If you create a LAMBDA called MYFUNCTION for example, you can call MYFUNCTION within the definition of MYFUNCTION. Reusable functions is reason enough to start taking advantage of LAMBDA, but there’s one more thing… you can do recursion. Then anywhere in your sheet, you can refer to MYFUNCTION, re-using that custom function throughout your sheet. With LAMBDA, you can take any formula you’ve built in Excel and wrap it up in a LAMBDA function and give it a name (like “MYFUNCTION”). For folks with a computer science background, you’re probably already familiar with the concept of lambdas, and the introduction of LAMBDA makes the Excel formula language Turing Complete. Moreover, one function can call another, so there is no limit to the power you can deploy with a single function call. In contrast, LAMBDA allows you to define a custom function in Excel’s own formula language. Excel already allows you to define custom functions, but only by writing them in an entirely different language such as JavaScript.
Simply put, LAMBDA allows you to define your own custom functions using Excel’s formula language. Excel formulas are the world’s most widely used programming language, yet one of the more basic principles in programming has been missing, and that is the ability to use the formula language to define your own re-usable functions. Today we are releasing to our Beta customers a new capability that will revolutionize how you build formulas in Excel.