Finding the position of a string in an array

[Brian_Reeds]

Hi Everyone,

I am struggling to develop a formula to determine which position in an array another field is located. Here is my example:

• The Array of Trans# is 2239, 4539, 4792, 8912, 10394
• I am trying to find a formula that says Trans# 4792 is in position 3, Trans# is in position 1, Trans# 8912 is in position 4, etc.

I can use FIND to tell me the starting position of the string, but cannot figure out to determine which position Trans# is.

Thanks so much in advance.

[kuovonne · Accepted solution]

Welcome to the Airtable community!

Do you want something like this?

It isn’t clear if your array is a text string, a lookup, or a rollup.
If your array isn’t a text string, you will need to convert it to one first. The exact method depends on the field types involved.

Here is a formula where both the “array” and the string to find are text fields. If either is a different field type, this formula will not work.

On the other hand, I am not sure what your use case is, and I wonder if there is some better solution that does not involve getting the exact position.

IF(
  AND(
    {Element},
    FIND(" " & {Element} & ",", " " & {Array As String} & ",")
  ),
  LEN(
    LEFT(" " & {Array As String} & ",", FIND(" " & {Element} & ",", " " & {Array As String} & ","))
  ) - 
  LEN(
    SUBSTITUTE(
      LEFT(" " & {Array As String} & ",", FIND(" " & {Element} & ",", " " & {Array As String} & ",")),
      ",",
      ""
    )
  ) + 1
)

[Brian_Reeds]

Thank so much - this worked brilliantly.

I am constantly amazed and the knowledge in this community.

[Benjamin_Gunter]

If you want to use Array Formulas, you can use the trick to change number to text in your Array Lookups

ARRAYJOIN(values,", ")&""

Then you can just remove all the extraneous quotations from above:

IF(
  AND(
    {Element},
    FIND({Element},{Array As String})
  ),
  LEN(
    LEFT({Array As String}, FIND({Element},{Array As String}))
  ) - 
  LEN(
    SUBSTITUTE(
      LEFT({Array As String}, FIND({Element},{Array As String})),
      ",",
      ""
    )
  ) + 1
)