You can create and return a custom function with a set of names and a formula_expression
that uses them. To calculate the formula_expression
, you can call the returned function with as many values as the name
declares.
Sample Usage
LAMBDA(Salary, Salary*0.3)(1000)
LAMBDA(Temp, (5/9)*(Temp-32))(85)
Syntax
LAMBDA(name, formula_expression)
name
: The name to be used inside theformula_expression
. This name must be an identifier and resolves to the actual value passed to the custom function returned byLAMBDA
.formula_expression
: The formula to be calculated. It uses names declared in previous parameters.
Notes
- If a named function expects another function as an input in an argument inside a named function, you can use a
LAMBDA
or a named function.
Examples
Example data:
LAMBDA standalone
You can write a LAMBDA
function to calculate salary tax, assuming that the tax rate is 30%. You input the salary value after the function.
Example: =LAMBDA(salary, salary*0.3)(C5)
This calculates the tax for month 1.
LAMBDA inside a LAMBDA helper function
To perform advanced array-operations, use LAMBDA
functions inside LAMBDA helper functions
(LHFs).
Example: =MAP(C5:C10, LAMBDA(salary, salary*0.3))
This performs the calculation of salary * 0.3 to each item in the C5:C10 array.
LAMBDA inside a named function
You can use LAMBDA
functions as a part of a named function’s argument. Learn more about named functions.
Named function: AVG_MONTHLY_TAX(range, tax_calculator_function)
Formula definition: =tax_calculator_function(sum(range))/count(range)
You can write the tax_calculator_function
argument with a LAMBDA
function.
Example: =AVG_MONTHLY_TAX(C5:C10,LAMBDA(range, range*0.3))
This calculates the average monthly tax for months 1–6.
Common errors
The name argument isn’t an identifier
Example: =LAMBDA(3, x+1)(3)
If the first argument isn't an identifier, this error occurs:
Identifier requirements:
- Can’t be ranges, like “A1” or “A2.”
- Can’t have spaces or special characters. Dots and underscores are allowed.
- Can’t start with numbers, like “9hello.”
The LAMBDA wasn’t called
This error is due to not following the LAMBDA
with the call that contains the values.
Example: =LAMBDA(salary, salary*0.3)
If no value is passed for salary
, this error occurs:
For a LAMBDA
, as an argument in a named function, this means not calling the placeholder referring to that LAMBDA
with the needed values inside the named function's definition.
Example: Under formula definition, if you write =tax_calculator_function/count(range)
instead of =tax_calculator_function(sum(range))/count(range)
, this error occurs:
Tip: For a LAMBDA
inside a LAMBDA helper function
, this error wouldn’t occur because the LAMBDA helper function
automatically uses the LAMBDA
on the given input range.
Lambda helper functions
Lambda helper functions
(LHFs) are native functions which accept a reusable LAMBDA
as an argument along with an input array(s). They help in advanced array-operations by executing the formula specified inside the LAMBDA
, on each value in the input array. The reusable LAMBDA
can be passed either as a LAMBDA
function or a named function
.
Lambda helper functions:
- MAP function: This function maps each value in the given arrays to a new value.
- REDUCE function: This function reduces an array to an accumulated result.
- BYCOL function: This function groups an array by columns.
- BYROW function: This function groups an array by rows.
- SCAN function: This function scans an array and produces intermediate values.
- MAKEARRAY function: This function creates a calculated array of specified dimensions.
Related functions
Create & use named functions: Let users create and store custom functions, similar toLAMBDA
.