https://www.pbainbridge.co.uk/2023/01/organise-files-into-javascript-object.html

Organise files into a JavaScript Object.gs

/*
Loop through a folder of CSV files.
Capture tutor name (from file name) and file ID in a JavaScript Object.
Collates/sorts all files together for each individual tutor.
End result is ability to loop through JavaScript Object and action CSV files
belonging to each tutor in-turn.

Collated data will look like this:
{"Jane Doe":["1-kh1Vp6It4LvVNSahUMkP529hu4-_es9","1z8O6jnm8INdZf9NWZBCoWTvB0zTEQDDe","1MnenQwueMKWssWlBOEaM8lcozB9ghYEn"],"Micky Mouse":["1BRv0IhTxYxhsYbDN85DkpMqrTPyJHXyK","1dmwVbPdwNQbOg9nfO98RD213QpKOLuqk"]}
*/


function readFiles() {

  // get folder of files
  var folder = DriveApp.getFolderById("ENTER ID HERE");

  // get all files in folder
  var files = folder.getFiles();


  // create empty JavaScript Object
  var obj = {};


  // loop through each file in folder ***********************************
  while (files.hasNext()) {

    // get the next file
    var theFile = files.next();

    // get the file name
    var theFileName = theFile.getName();

    // get the file Id
    var theFileId = theFile.getId();

    // check file name ends with '.csv' to avoid picking up the Google Sheet file in the process
    if (theFileName.endsWith(".csv")) {


      // split the file name into 3 chunks to extract relevant info
      var items = theFileName.split(" - ");
      var moduleCode = items[0];  // collected but not going to be used in this example
      var tutor = items[1];
      var group = items[2];  // collected but not going to be used in this example


      // see if the tutor already exists in the JavaScript Object **********
      if (obj[tutor] == null) {

        // the Object has not seen this tutor yet

        // create an array in that tutor with first file Id in there.
        obj[tutor] = [theFileId];

      }
      else {

        // the Object knows about this tutor

        // so add one (the current file Id) onto the existing array.
        obj[tutor].push(theFileId);

      }
      // see if the tutor already exists in the JavaScript Object **********


    }
  }
  // loop through each file in folder ***********************************



  // now that all files have been read, do something with this JavaScript Object *********************

  /*
  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of - the 'for ... of' statement executes a loop that operates on a sequence of values sourced from an iterable object (eg an array).

  2 variables are created (tutor and fileIds) as the Object is then iterated over as an array.
  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries - the 'Object.entries()' method returns an array of a given object's own enumerable string-keyed property [key, value] pairs. 
  */

  // get Object as an array for iterating through for tutors and corresponding file Ids
  var arrayToIterate = Object.entries(obj);
  Logger.log(arrayToIterate);

  for (var [tutor, fileIds] of arrayToIterate) {

    // the is where the Google Sheet file would be created for the tutor

    // loop through the file Ids for each tutor ***************
    for (fileId of fileIds) {

      Logger.log(tutor + "\t" + fileId);

      // open the file and read its data
      // create a tab in the Google Sheet for this given file
      // put the data into this tab
    }
    // loop through the file Ids for each tutor ***************

    // delete the 'Template' tab and sort order

  }
  // now that all files have been read, do something with this object *********************




  for (tutor of arrayToIterate) {

    // log array for each tutor and their corresponding file Ids
    Logger.log(tutor);

    // log array of all file Ids for given tutor
    var fileIds = tutor[1];
    Logger.log(fileIds);


    // the is where the Google Sheet file would be created for the tutor

    // loop through the file Ids for each tutor ***************
    for (var i = 0; i < fileIds.length; i++) {

      // extract specific fileId
      var fileId = fileIds[i];
      Logger.log('single fileId is: ' + fileId);

      // open the file and read its data
      // create a tab in the Google Sheet for this given file
      // put the data into this tab

    }
    // loop through the file Ids for each tutor ***************

    // delete the 'Template' tab and sort order

  }


}