# Get last entry by month and year

*Note: the lookup_value of 2 is deliberately larger than any values in the lookup_vector, following the concept of bignum.*

Working from the inside out, the expression:

generates strings like "0117" using the values in column B and E, which are then compared to each other. The result is an array like this:

{TRUE;TRUE;TRUE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE}

where TRUE represents dates in the same month and year. The number 1 is then divided by this array. The result is an array of either 1's or divide by zero errors (#DIV/0!):

{1;1;1;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!}

which goes into LOOKUP as the lookup array. LOOKUP assumes data is sorted in ascending order and always does an approximate match. When the lookup value of 2 can't be found, LOOKUP will match the previous value, so lookup will match the last 1 in the array.

Finally, LOOKUP returns the corresponding value in result_vector, which contains the amounts in C5:C13.` `

## Excel Formula Training

Formulas are the key to getting things done in Excel. In this accelerated training, you'll learn how to use formulas to manipulate text, work with dates and times, lookup values with VLOOKUP and INDEX & MATCH, count and sum with criteria, dynamically rank values, and create dynamic ranges. You'll also learn how to troubleshoot, trace errors, and fix problems. Instant access. See details here.

## Download 100+ Important Excel Functions

Get over 100 Excel Functions you should know in one handy PDF.