# How to replicate Sheets’ FLATTEN function in Excel

Wednesday’s announcement of 14 new Excel functions was welcoming news.

However, despite switching to the BETA Channel yesterday, I am not one of the lucky ones who have access to the new batch yet.

Nevertheless, I was particularly drawn to the TOCOL function (https://lnkd.in/edtG7VuR), which appears to be Excel’s answer to Google Sheets’ FLATTEN.

FLATTEN flattens all the values from one or more ranges into a single column.

There have been numerous occasions over the years where I’ve wanted to do this in Excel but haven’t been able to (easily) due to the lack of native function. Thankfully, in more recent times it’s been possible to create a LAMBDA that largely replicates it.

It’s going to be a while before TOCOL has widespread availability, so in the meantime, use FLATTEN!

## Function Syntax

FLATTEN ( 𝚊𝚛𝚛𝚊𝚢 )

• 𝚊𝚛𝚛𝚊𝚢 — the array or reference to return as a column

## Example

Cell D3 uses FLATTEN to reference the 𝗗𝗮𝘁𝗮 table values, which contains the numbers 1–10 spelt out. E2 shows the function’s composition, and each part is broken down in columns G to L.

The following named values are stored inside LET:

• 𝙧𝙤𝙬𝙨 — 5 rows in the 𝗗𝗮𝘁𝗮 table.

• 𝙘𝙤𝙡𝙪𝙢𝙣𝙨 — 2 columns in the 𝗗𝗮𝘁𝗮 table.

• 𝙨𝙚𝙦𝙪𝙚𝙣𝙘𝙚 — multiplies the 𝗗𝗮𝘁𝗮 table rows by its columns to create a sequence of numbers from 1 to 10.

• 𝙦𝙪𝙤𝙩𝙞𝙚𝙣𝙩 — QUOTIENT returns the integer portion of a division. In 𝚗𝚞𝚖𝚎𝚛𝚊𝚝𝚘𝚛, 1 is subtracted from each of the 𝙨𝙚𝙦𝙪𝙚𝙣𝙘𝙚 figures. These are then divided by 2 (columns) in 𝚍𝚎𝚗𝚘𝚖𝚒𝚗𝚊𝚝𝚘𝚛 and 1 is added to generate an array with two of each row number, e.g. 1, 1; 2, 2; 3, 3, etc.

• 𝙢𝙤𝙙 — MOD returns the remainder after 𝚗𝚞𝚖𝚋𝚎𝚛 is divided by 𝚍𝚒𝚟𝚒𝚜𝚘𝚛. The calculation is the same as 𝙦𝙪𝙤𝙩𝙞𝙚𝙣𝙩, except the result consists of an alternating 1 and 2.

With the named values defined, the main calculation can now be constructed (column L).

Nested inside the INDEX 𝚊𝚛𝚛𝚊𝚢 argument is an IF statement ensuring any blank values in the 𝗗𝗮𝘁𝗮 table are returned as empty strings.

The quotient and mod values in columns J and K represent 𝚛𝚘𝚠_𝚗𝚞𝚖 and [𝚌𝚘𝚕𝚞𝚖𝚗_𝚗𝚞𝚖], respectively. This pattern of numbers allows the correct values to be grabbed from the 𝗗𝗮𝘁𝗮 table and displayed in a single column.

## Limitations

Unfortunately, certain disadvantages do exist compared to Google’s FLATTEN. Non-contiguous ranges are not permitted so all columns must be adjacent to each other. That also means different sized ranges are forbidden.

From my understanding, TOCOL does not have these limitations.

GitHub Gist — https://lnkd.in/eVtUwYib