[SOLVED] How to dynamically update reference cell in an if loop in Google Apps Script setFormula function

How to dynamically update reference cell in an if loop in Google Apps Script setFormula function

I'm trying to change the reference cell in the DATE function in an if loop in Apps Script. The cell I'm referencing is formatted in the following way: "2020-01-31 14:26:58." Here is what I got so far:

 var s = SpreadsheetApp.getActive().getSheetByName("Prep");
 var data = s.getRange("I2:I").getValues();
 var data_len = data.length;

 for(var i=0; i<data_len; i++) {
      if(data[i][0].length !== 0) {
        s.getRange(i+2,4).activate();
        s.getCurrentCell().setFormula('=TEXT(DATE(2020,MID(I2,6,2),1),"mmmm")');
      } else {
      }
    }

This works fine if all of the data is from the same month. However, I'm trying to get I2 to update to I3, I4...IX as I go through the loop so that if the data references more than one month, it will be changed accordingly. I've tried Googling solutions and looking at videos and posts but I can't figure it out.

Markdown Example (Bolded text is what I want the output to show):

Link	Type	Year	Month	First Name	Last Name	Gender	Age	Application Submitted
-	Applicant	2020	January	John	Doe	M	40	2020-01-31 14:26:58
-	Applicant	2020	February	Jill	Bradley	F	45	2020-02-15 11:50:06
-	Applicant	2020	March	Jane	Alice	F	41	2020-03-31 10:36:04

Solution

You could use the value of i to set the value dynamically:

    s.getCurrentCell().setFormula('=TEXT(DATE(2020,MID(I'+(i+2)+',6,2),1),"mmmm")');

Other option would be to set an array of formulas and use only once setFormulas

And a third option is not to use a script but an array formula in D1 (first, delete all formulas in that column:

=VSTACK("Header",MAP(I2:I,LAMBDA(each,  IF(each="","",TEXT(DATE(2020,MID(each,6,2),1),"mmmm"))))