Two New Functions; Let and Lambda

Two new Excel functions have recently attracted a lot of attention; these are:

  • LET (now available to Office 365 subscribers and
  • LAMBDA (currently available to Office Insiders program only)

Microsoft documentation can be found at: Announcing LET

Have you ever had to repeat the same expression multiple times within a formula, created a mega formula or wished that you had a way to reuse portions of your formula for easier consumption? With the addition of the LET function, now you can!

Introducing LET

LET allows you to associate a calculation or value in your formula with a name. It’s names except on a formula level.

LAMBDA: The ultimate Excel worksheet function

In December 2020, we announced LAMBDA, which allows users to define new functions written in Excel’s own formula language, directly addressing our second challenge. These newly defined functions can call other LAMBDA-defined functions, to arbitrary depth, even recursively. With LAMBDA, Excel has become Turing-complete. You can now, in principle, write any computation in the Excel formula language. LAMBDA is available to members of the Insiders: Beta program. The initial release has some implementation restrictions that we expect to lift in the future. We discussed LAMBDA and some of our research on spreadsheets in a sponsored video presented at POPL 2021.

Further documentation and lengthy user discussion on the LAMBDA function

Examples of the LET function from

Using LET function in Excel with formula examples

Discussion of the advantahes and limitations of the LAMBDA function:

What Makes Excel’s Lambda Functions so Awesome (and what doesn’t)?

I will follow up in later posts with my own comments, including comparison with my VBA Eval function, and linking to similar, and better functionality with Python and pyxll.

This entry was posted in Excel, UDFs and tagged , , , , . Bookmark the permalink.

2 Responses to Two New Functions; Let and Lambda

  1. Pingback: Eval and Let examples | Newton Excel Bach, not (just) an Excel Blog

  2. Pingback: Lambda and VBA | Newton Excel Bach, not (just) an Excel Blog

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