Why Lambda is Central to the New Excel

At The New Excel, we consider Lambda so essential to the new way of approaching Excel that we’ve integrated it into our logo! But what is a lambda? And why is it so important to Excel?

At the most basic level, lambdas are nameless functions that perform a calculation defined within the lambda. For example, =LAMBDA(x, x^2) squares the provided number. Although lambdas exist in different programming languages, in Excel, LAMBDA provides a way to define a custom, reusable function. Deploying LAMBDA functions in Excel offers three big advantages:

• Leveraging Dynamic Array Functions. Dynamic Array Functions (DAFs) allow a single formula to perform calculations over a range of cells. They can take a range of cells as inputs and return a range of cells as outputs. Using DAFs within lambdas allows you to combine, manipulate, and arrange blocks of data one step at a time.
• Reducing the Need for VBA. LAMBDA replaces the need for user-defined functions written in VBA. This can improve overall calculation speed by taking advantage of Excel’s internal calculation engine (instead of making external calls to Visual Basic). By negating the need for VBA for custom functions, LAMBDA facilitates the use of .xlsx files over .xlsm/.xlsb files, easing file-sharing.
• Improving Auditability. We use the phrase, “Vet once. Trust always.” Lambda functions are reusable across a workbook. So once the logic is vetted for accuracy, it can be trusted to produce consistent results wherever it is used, just like built-in Excel functions. By baking mission-critical logic into custom functions, you can turn Microsoft’s Excel into Your Excel.

At The New Excel, we embrace a new approach to Excel. We look at workbooks in terms of ranges, blocks, and concepts. We don’t view them as collections of individual cells. Combining these three aspects of lambas, we now have a full-fledged programming language available on the worksheet side of Excel.

As a result, workbooks are no longer documents. They’re applications. And that is why LAMBDA changes everything.