LAMBDA

The LAMBDA function creates custom functions, enabling you to write reusable formulas with different inputs. It also supports advanced features like recursion and higher-order functions.

=LAMBDA(Parameter 1 [; Parameter 2 [; ... [; Parameter n]...]]; Formula)

Parameter 1: (required) The name of the first parameter to the function. The name must follow the range naming rules and cannot be the output of a reference or text formula. The scope of the parameter name is restricted to the LAMBDA function.

Parameter 2, ..., n : (optional). Additional parameters for the function. The same naming rules for Parameter 1 applies.

Formula: a formula expression. It must be the last argument of the function.

Usage

1. For better readability, it is recommended (though optional) to assign a name to the cell containing the LAMBDA function.

2. Create the LAMBDA function expression in the named cell above (by default, the cell will display the character λ).

3. Use the named cell, passing the parameters for the LAMBDA function.

Example of a simple geometric mean

1. Assign name MY_MEAN to cell A1.

2. Enter =LAMBDA(Number1;Number2;SQRT(Number1*Number2)) in cell A1.

3. In cell B1, enter =MY_MEAN(2;3).

4. Cell B1 displays the number 2.44948974278318, the square root of 2 times 3.

Example of a recursive call of a LAMBDA function

1. Assign name MY_FACTORIAL to cell A1

2. Enter =LAMBDA(n,IF(n>1,n*MY_FACTORIAL(n-1),1)) in cell A1

3. Enter =MY_FACTORIAL(5) in cell B1

4. Cell B1 will show 120.

Using ISOMITTED in function LAMBDA

The ISOMITTED function allows you to handle missing parameters in a LAMBDA function. For example, the LAMBDA function in cell A1:

=LAMBDA(_n1, _n2, IF(ISOMITTED(_n2), "Missing second parameter", _n1/_n2))

returns "Missing second parameter" if the LAMBDA function is called as =A1(3;). Note: The trailing argument separator (;) must be included in the function call.

COM.MICROSOFT.LAMBDA