The INDEX function in Excel returns a value according to its position in a table.
VLOOKUP vs INDEX
For many people, the difference between the functions VLOOKUP or INDEX is not obvious. In fact, the difference is quite simple.
- VLOOKUP searches by value (employee name, product name, product code, ...)
- INDEX searches by position (for instance returns the value in column 2 and row 5)
There is no difference between the two functions in terms of search speed.
Presentation of the function INDEX
The function INDEX works with three arguments:
- References of a range of cells containing the value to return
- The row position
- The column position
The order of parameters is very important. Often, users reverse the setting of the row and the column and inevitably, the function does not return the correct result.
Example: INDEX to return the month name
- Let's say, you have the list of the months' names on a worksheet.
- What is month #6?
- Well, with the function INDEX, it's easy to find the answer.
But of course, we can replace the value 6 with the reference of a cell, like this
Now, If the data source is in a row, the writing of the function is a little bit different.
- The second argument is = 1 (search on the first row)
- The third argument is the position
Function to return the position
So, INDEX expects a rank to return a value in your reference table. But if you have a huge list of values on your table, like customers' names, how to find the position of the clients Smith or Garcia?
This is where the function MATCH will help you to convert a value to a position 😉
Here, for instance, we select a month and the function MATCH returns the rank.
Function INDEX with 2 dimensions
The INDEX function is very powerful with a 2-dimensional array. Like that, you can return the value of a cell inside a grid of data. This is how most Excel users use this function.
For example, we want to return the distance between 2 cities (the explanation to build such a cross table in this article)
So here, we must convert the name of the cities as a position with the function MATCH
Then, we will use this information in the INDEX function to return the distance between the cities
It is compulsory that your selection does NOT include the headers.