Category: Spreadsheets

Google Sheets REGEX Formulas

This post explores the Google Sheets REGEX formulas with a series of examples to illustrate how they work.

Regular expressions, or REGEX for short, are tools for solving problems with text strings. They work by matching patterns.

You use REGEX to solve problems like finding names or telephone numbers in data, validating email addresses, extracting URLs, renaming filenames containing the word “Application” etc.

They have a reputation for being hard, but once you learn a few basic rules and understand how they work you can use them effectively.

There are three Google Sheets REGEX formulas: REGEXMATCH, REGEXEXTRACT, and REGEXREPLACE.

Each has a specific job:

• REGEXMATCH will confirm whether it finds the pattern in the text.

• REGEXEXTRACT will extract text that matches the pattern.

• REGEXREPLACE will replace text that matches the pattern.

Let’s understand them with a series of examples.

Google Sheets REGEX Formula Cookbook💡 Learn more
Learn more about REGEX formulas in my latest course: The Google Sheets REGEX Formula Cookbook

Continue reading Google Sheets REGEX Formulas

Use The SWITCH Function to Categorize Data Efficiently

The SWITCH function is a useful tool for categorizing data. In the right circumstances, it can save you from messy, nested IF functions.

The SWITCH function is used to test an expression against a list of cases. It returns a value when the expression is equal to one of the cases.

It has some similarities to the IFS function but differs because SWITCH tests for exact matching rather than whether a condition is true (e.g. X > Y). SWITCH also has a default option to return a value if no match is found.

Let’s see an example. Suppose we have this data set of student grades and we want to add context to each grade level.

SWITCH function with student grades

Use this SWITCH function to categorize these grades:

=SWITCH(B2,
"A","Top marks! Great job!",
"B","Keep up the good work",
"C","Could do better",
"Failed. Remedial study needed")

Let’s break it down:

B2 is the condition we’re going to test. It’s the grade letter from column B and it’s the input to our SWITCH function.

We check the value of B2 against the first case “A”. If they match (i.e. the grade in B2 was also “A”) then SWITCH returns the string “Top marks! Great job!”.

If the value from B2 doesn’t match “A”, we move on and test it against “B”  and if that fails, test against “C”.

If the condition doesn’t match any of the cases, the last string is returned: “Failed. Remedial study needed”. It’s our catch-all solution. Anything that’s not “A”, “B” and “C” will return this answer.

This is what the solution looks like:

Switch Function in Google Sheets

Give it a try and SWITCH things up!

The FACT Function in Google Sheets (And Why A Shuffled Deck of Cards Is Unique)

Let’s start with a mind-blowing fact, and then use the FACT function in Google Sheets to explain it.

Pick up a standard 52 card deck and give it a good shuffle.

The order of cards in a shuffled deck will be unique.

One that has likely never been seen before in the history of the universe and will likely never be seen again.

I’ll let that sink in.

Isn’t that mind-blowing?

Especially when you picture all the crazy casinos in Las Vegas.

Let’s understand why, and in the process learn about the FACT function and basic combinatorics (the study of counting in mathematics).

Four Card Deck

To keep things simple, suppose you only have 4 cards in your deck, the four aces.

You can create this deck in Google Sheets with the CHAR function:

CHAR cards

The formulas to create these four cards are:

Ace of Clubs:

=CHAR(127185)

Ace of Spades:

=CHAR(127137)

Ace of Hearts:

=CHAR(127153)

Ace of Diamonds:

=CHAR(127169)

Let’s see how many different combinations exist with just these four cards.

Pick one of them to start. You have a choice of four cards at this stage.

Once you’ve chosen the first one, you have three cards left, so there are 3 possible options for the second card choice.

When you’ve picked that second card, you have two cards left. So you have a choice of two for the third card.

The final card is the last remaining one.

So you have 4 choices * 3 choices * 2 choices * 1 choice = 4 * 3 * 2 * 1 = 24

There are 24 permutations (variations) with just 4 cards!

Visually, we can show this in our Google Sheet by displaying all the different combinations with the card images from above:

Fact function card combinations in Google Sheets

(I’ve just shown the first 6 rows for brevity.)

You can see for example, when moving from row 1 to row 2, we swapped the position of the two red suits: the Ace of Hearts and the Ace of Diamonds.

Five Card Deck

This time there are 5 choices for the first card, then 4, then 3, then 2, and finally 1.

So the number of permutations is 5 * 4 * 3 * 2 * 1 = 120

Already a lot more! I have not drawn this out in a Google Sheet and leave that as an optional exercise for you if you wish.

The FACT function

The FACT function in Google Sheets (see documentation) is a math function that returns the factorial of a given number. The factorial is the product of that number with all the numbers lower than it down to 1.

In other words, exactly what we’ve done above in the above calculations.

Four:

The 4 card deck formula is:

=FACT(4)

which gives an answer of 24 permutations.

Five:

The 5 card deck formula is:

=FACT(5)

which gives an answer of 120 permutations.

Six:

A 6 card deck is:

=FACT(6)

which gives an answer of 720 permutations.

Twelve:

A 12 card deck has  479,001,600 different ways of being shuffled:

=FACT(12)

(You’re more likely to win the Powerball lottery at 1 in 292 million odds than to get two matching shuffled decks of cards, even with just 12 cards!)

Fifty Two:

Keep going up to a full deck of 52 cards with the formula and it’s a staggeringly large number.

=FACT(52)

Type it into Google Sheets and you’ll see an answer of 8.07E+67, which is 8 followed by 67 zeros!

(This number notation is called scientific notation, where huge numbers are rounded to the first few digits multiplied by a 10 to the power of some number, 67 in this case.)

This answer is more than the number of stars in the universe (about 10 followed by 21 zeros).

Put another way if all 6 billion humans on earth began shuffling cards at 1 deck per minute every day of the year for millions of years, we still wouldn’t even be close to finding all possible combinations.

Unpivot In Google Sheets With Formulas (How To Turn Wide Data Into Tall Data)

Unpivot in Google Sheets is a method to turn “wide” tables into “tall” tables, which are more convenient for analysis.

Suppose we have a wide table like this:

Wide Data Table

Wide data like this is good for the Google Sheets chart tool but it’s not ideal for creating pivot tables or doing analysis. The main reason is that data is captured in the column headings, which prevents you using it in pivot tables for analyis.

So we want to transform this data — unpivot it — into the tall format that is the way databases store data:

Unpviot in Google Sheets

But how do we unpivot our data like that?

It turns out it’s quite hard.

It’s harder than going the other direction, turning tall data into wide data tables, which we can do with a pivot table.

This article looks at how to do it using formulas so if you’re ready for some complex formulas, let’s dive in…

Unpivot in Google Sheets

We’ll use the wide dataset shown in the first image at the top of this post.

The output of our formulas should look like the second image in this post.

In other words, we need to create 16 rows to account for the different pairings of Customer and Product, e.g. Customer 1 + Product 1, Customer 1 + Product 2, etc. all the way up to Customer 4 + Product 4.

Of course, we’ll employ the Onion Method to understand these formulas.

Template

Click here to open the Unpivot in Google Sheets template

Feel free to make your own copy (File > Make a copy…).

(If you can’t open the file, it’s likely because your G Suite account prohibits opening files from external sources. Talk to your G Suite administrator or try opening the file in an incognito browser.)

Step 1: Combine The Data

Use an array formula like this to combine the column headings (Customer 1, Customer 2, etc.) with the row headings (Product 1, Product 2, Product 3, etc.) and the data.

It’s crucial to add a special character between these sections of the dataset though, so we can split them up later on. I’ve used the fox emoji (because, why not?) but you can use whatever you like, provided it’s unique and doesn’t occur anywhere in the dataset.

=ArrayFormula(B1:E1&"🦊"&A2:A4&"🦊"&B2:E4)

The output of this formula is:

Unpivot Data In Google Sheets Step 1

Step 2: Flatten The Data

Before the introduction of the FLATTEN function, this step was much, much harder, involving lots of weird formulas.

Thankfully the FLATTEN function does away with all of that and simply stacks all of the columns in the range on top of each other. So in this example, our combined data turns into a single column.

=ArrayFormula(FLATTEN(B1:E1&"🦊"&A2:A4&"🦊"&B2:E4))

The result is:

Unpivot Data In Google Sheets Step 2

Step 3: Split The Data Into Columns

The final step is to split this new tall column into separate columns for each data type. You can see now why we needed to include the fox emoji so that we have a unique character to split the data on.

Wrap the formula from step 2 with the SPLIT function and set the delimiter to “🦊”:

=ArrayFormula(SPLIT(FLATTEN(B1:E1&"🦊"&A2:A4&"🦊"&B2:E4),"🦊"))

This splits the data into the tall data format we want. All that’s left is to add the correct column headings.

Unpivot Data In Google Sheets Step 3

Unpivot With Apps Script

You can also use Google Apps Script to unpivot data, as shown in this example from the first answer of this Stack Overflow post.

Further Reading

For more information on the shape of datasets, have a read of Spreadsheet Thinking vs. Database Thinking.

IFS Function in Google Sheets

The IFS function in Google Sheets is used to test multiple conditions and outputs a value specified by the first test that evaluates to true.

It’s akin to a nested IF formula, although it’s not exactly the same. However, if you find yourself creating a nested IF formula then it’s probably easier to use this IFS function.

Continue reading IFS Function in Google Sheets