https://www.pbainbridge.co.uk/2023/01/organise-files-into-javascript-object-20.html

Organise files into a JavaScript Object 2.0.gs

/*
Loop through a folder of CSV files.
Capture tutor name (from file name) and code the file ID / Module Code / Group No with it 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:
{Micky Mouse=[{fileId=1BRv0IhTxYxhsYbDN85DkpMqrTPyJHXyK, group=Grp 05.csv, moduleCode=CDE}, {moduleCode=CDE, fileId=1dmwVbPdwNQbOg9nfO98RD213QpKOLuqk, group=Grp 01.csv}], Jane Doe=[{group=Grp 04.csv, fileId=1z8O6jnm8INdZf9NWZBCoWTvB0zTEQDDe, moduleCode=ABC}, {moduleCode=ABC, fileId=1MnenQwueMKWssWlBOEaM8lcozB9ghYEn, group=Grp 03.csv}, {fileId=1-kh1Vp6It4LvVNSahUMkP529hu4-_es9, moduleCode=ABC, group=Grp 02.csv}]}
*/


function readFiles2() {

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

  // 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];
      var tutor = items[1];
      var group = items[2];


      // 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 file info.
        obj[tutor] = [{ fileId: theFileId, moduleCode: moduleCode, group: group }];

      }
      else {

        // the Object knows about this tutor

        // so add the current file info onto the existing array.
        obj[tutor].push({ fileId: theFileId, moduleCode: moduleCode, group: group });

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


    }
    else {
      // not .csv file so skip
    };
  }
  // 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 fileObjs) 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 info
  var arrayToIterate = Object.entries(obj);
  Logger.log(arrayToIterate);

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

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

    // loop through the file Objects for each tutor ***************
    for (fileObj of fileObjs) {

      // extract File ID
      var fileId = fileObj.fileId;

      // extract Module Code
      var modCode = fileObj.moduleCode;

      // extract Group
      var group = fileObj.group;

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

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




  for (tutor in obj) {

    // return the JavaScript Object as an Array to loop through each tutor
    var theArrayOfObjects = obj[tutor];


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


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

      // get the Object for specific tutor
      var fileObj = theArrayOfObjects[i];

      // log the tutor
      Logger.log('Tutor is: ' + tutor);

      // extract file ID
      var fileID = fileObj.fileId;
      Logger.log('single fileID is: ' + fileID);

      // extract module code
      var modCode = fileObj.moduleCode;
      Logger.log('single modCode is: ' + modCode);

      // extract group
      var group = fileObj.group;
      Logger.log('single group is: ' + group);

      // insert Line Break for Logging
      Logger.log('\n');

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

    // delete the 'Template' tab and sort order

  }


}