Reduces an array to an accumulated value by applying a LAMBDA to each value and returning the total value in the accumulator.

## Syntax

=REDUCE([initial_value], array, lambda(accumulator, value))

The REDUCE function syntax has the following arguments and parameters:

• [initial_value]    Sets the starting value for the accumulator.

• array      An array to be reduced.

• lambda      A LAMBDA that is called to reduce the array. The LAMBDA takes two parameters:

• accumulator    The value totaled up and returned as the final result.

• value     The calculation applied to each element in the array.

## Remarks

Use the initial_value argument to set the starting value for the accumulator parameter. In Example 2, where you multiply the accumulator, set the value to 1 to avoid multiplying by 0.

## Errors

Providing an invalid LAMBDA function or an incorrect number of parameters returns a #VALUE! error called "Incorrect Parameters".

## Examples

Example 1: Sum the squared values

Enter the sample data into cells A1:C2, and then copy the formula into cell D4:

=REDUCE(, A1:C2, LAMBDA(a,b,a+b^2))

Example 2: Create a customized "PRODUCTIF" function to multiply only values greater than 50

Create a table named "Table2" with one column named "Nums" starting at cell E1. Copy the following formula into cell G2:

=REDUCE(1,Table2[Nums],LAMBDA(a,b,IF(b>50,a+b,a)))

Example 3: Count only even values

Create a table named "Table4" with one column named "Nums" starting at cell D1. Copy the following formula into cell F2:

=REDUCE(0,Table4[Nums],LAMBDA(a,n,IF(ISEVEN(n),1+a, a)))