The LEFT function in Google Sheets is useful to return a substring from the beginning of a specified string.
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LEFT function is one of the text functions that let you format your text values (strings) in Google Sheets.
Let’s take an example.
Say you have product codes of clothes that contain several numbers, letters and special characters.
To get the category of products, you need to cut the beginning of the text values until the first ‘_’ underscore character.
So how do we do that?
It’s pretty simple.
LEFT function just needs an input string and the length of the substring to extract it.
Let’s dive right into some examples to see how we can write our own LEFT function in Google Sheets.
The Anatomy of the LEFT Function
The syntax of the function defines how we should work with it. The syntax of the
LEFT function is as follows:
Let’s understand what the LEFT function and its attributes mean:
=the equal sign is how we start just about any function in Google Sheets.
LEFTis our function. We will have to add the corresponding arguments
number_of_characters(optional) into it for it to work.
stringis the input text from which the function returns the left part.
number_of_charactersis an optional argument. It specifies the number of characters to return from the left side of the text. Its default value is 1, so in case the number is not specified, the function returns the single leftmost character in the string.
A Real Example of Using LEFT Function
Let’s look at the example below to see how to use the LEFT function in Google Sheets.
This sheet contains a list of products, and each product has a long identification code that we call Product ID in column B.
Our task is to extract the left side of these IDs until the first underscore and write it as Category ID in column C.
LEFT Function With Static Number of Characters
In the example above, it’s pretty simple. If you look at the sheet, you can see that the Product IDs always have 3 numeric characters on the left side of the first underscore symbol.
So we use a static (non-changing) value to extract the left part of the strings.
The following formula will extract the first three characters of the cell content of B2:
However, we want to apply the same formula to all of the products in the sheet, not only the first one.
- One option to do write (or drag down) the same function into all of the cells of column C.
- Another way is to use the
ARRAYFORMULAfunction. If you want to know more about how to use ARRAYFORMULA function in Google Sheets, check out our article on that.
So, we can add the
ARRAYFORMULA to our
LEFT function as follows:
Here’s what this example does:
LEFTfunction has two arguments. The first one is the text value we want to use, so the
stringargument. These text values are present in column B from cell B2 to cell B7. Therefore we wrote B2:B7.
- The second argument of the
LEFTfunction is the
number_of_characters, which is 3 in our example.
- We used the
ARRAYFORMULAfunction to apply the function to the whole array of products.
It’s simple, isn’t it?
LEFT Function With Dynamic Number of Characters
Let’s change the Product IDs to see how to use the LEFT function in a little bit more complicated example.
We don’t want to extract the first three numeric characters anymore, but we need numbers of different lengths before the first underscore symbol.
So what can we do now?
We can use the
FIND function additionally. The FIND function in Google Sheets is used to return the position at which a string is first found within the text.
This way, we look for the first underscore characters dynamically.
The function to put in cell C2 is as follows:
Let’s see what happens here:
- As before, we use the
LEFTfunction with two arguments. The first argument (
string) doesn’t change. It’s still the range B2:B7 where the original string values are.
- The second argument is the whole
FINDformula: FIND(“_”, B2:B7)-1.
- We started with the name of the
FINDfunction followed by the character we want to find. This character is the “_” underscore character, and we had to put it between quotation marks.
- Then we added the range of cells where we are looking for the specified character. The range is the same B2:B7 where our text values are.
- After that, we subtracted 1. We needed this –1 because the
FINDfunction gives us the position of the first underscore character. However, we want to extract the substrings before that character, so we subtract one. For example, if the underscore is the 5th character in a string, then we need the first four characters of the string.
- We used the
ARRAYFORMULAto apply the function to the whole list of products. As a result, we extracted the numeric characters from the beginning of the strings, even though their lengths are different.
You can make a copy of the spreadsheet below and try it for yourself:
How to Use LEFT Function in Google Sheets
Let’s see how to write your own
LEFT function, step-by-step.
- To start, click on the cell where you want to show your result to make it the active cell. For this guide, I will be selecting C2, where I extracted the first substring.
- Next, type the equal sign ‘=’ to begin the function. Then followed by the name of the function which is ‘
LEFT, whichever works).
- Now you should see that the auto-suggest box will pop-up with the name of the functions that start with
LEFT. There are more of them, so make sure to select the right one!
- After the opening bracket ‘(‘, you have to add the right arguments. Firstly, highlight the cell that has the original text value. In my example, I click on the cell B2.
- After that, add a comma to separate the values and write the required
number_of_charactersyou want to return from the left side of your string. I’m writing 3 here to extract the first three characters of my string.
- Now you can hit your Enter key to get the result of this single product immediately.
- Let’s see how should you apply the function to the whole list of products using
ARRAYFORMULA. To make it work, type
ARRAYFORMULAat the beginning of the whole function after the ‘=’ equal sign and then add the ‘(‘ opening bracket.
- When working with
ARRAYFORMULA, you also need to change the cell references to ranges of cell references. So, instead of using B2 as the text argument, change it to the whole range of cells, to B2:B7 in my example.
- Close the brackets and hit Enter! You can see your results in the whole array.
That’s it, well done! You can now use the
LEFT function together with the other numerous Google Sheets formulas to create even more powerful formulas that can make your life much easier. 🙂