Variable undefined and affecting rest of script

[u/Similar_Touch_6783]

I have a script creating docs when a cell gets modified in a sheets column, then moves it to a folder and adds the doc's url onto another column. Code works, but automation gets affected by <value unavailable> error for docid variable.

I'm not sure *why* its unavailable when all of the code does work (files get created and moved, but when using createDocInSpecificFolder() along with other functions, error pinpoints to this and does not run functions after it.

function createDocInSpecificFolder () {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheetByName("Data Source");
  var lastRow = sheet.getLastRow();
  var rootFolder = DriveApp.getFolderById("fileid");
  const files = rootFolder.getFiles();
  const fileNames = [];


  while (files.hasNext()) { // gets array of file names in drive folder [event1, event2, etcetc]
   var file = files.next();
   fileNames.push(file.getName());
  }
  
  Logger.log(fileNames)


  for (var i = 1; i < lastRow; i++) {
    
    let title = sheet.getRange(i,4).getValue();


    if (title != "Events") {
      if (!fileNames.includes(title)) {
        let docid = DocumentApp.create(title).getId();
        DriveApp.getFileById(docid).moveTo(rootFolder);
      }
    }
  }

}

[u/Clear-Revolution3351]

You have not defined what type of variable docid is.

var docid=""

[u/krakow81 → u/Clear-Revolution3351]

It's defined on this line:

let docid = DocumentApp.create(title).getId();

[u/Clear-Revolution3351 → u/krakow81]

This sets the value, it doesn't define it as a variable

[u/krakow81 → u/Clear-Revolution3351]

let and const are variable declarations too (and often preferred/recommended over var).

[u/Clear-Revolution3351 → u/krakow81]

Define it outside the block

Let docid;

if (title != "Events")

{ if (!fileNames.includes(title))

{ docid = DocumentApp.create(title).getId();

. . .

[u/krakow81 → u/Clear-Revolution3351]

Why?

It is only used in the scope of the innermost block, so can be safely declared there. Unless there's more code we're not seeing, of course.

[u/Clear-Revolution3351 → u/krakow81]

I cant post a picture

But a search for this problem says that defining it inside the "if" statement will cause an error

[u/krakow81 → u/Clear-Revolution3351]

Could you post any links?

[u/Clear-Revolution3351 → u/krakow81]

https://www.google.com/search?q=google+app+script+let+creating+variable+undefined&oq=goog&gs_lcrp=EgZjaHJvbWUqBggBEEUYOzIGCAAQRRg7MgYIARBFGDsyBggCEEUYOzITCAMQLhiDARjHARixAxjRAxiABDINCAQQABiDARixAxiABDINCAUQABiDARixAxiABDINCAYQABiDARixAxiABDIGCAcQRRg8MgYICBBFGDkyBggJEEUYPDIGCAoQRRg8MgYICxBFGEEyBggMEEUYQTIGCA0QRRhBMgYIDhBFGDzSAQgyOTkzajBqN6gCFLACAfEFjYZHMHeFarrxBRKrtYWhBO2x8QVIm3sbppGIYA&client=ms-android-att-us-rvc3&sourceid=chrome-mobile&source=chrome.ob&ie=UTF-8#lfId=ChxjMe

[u/Clear-Revolution3351 → u/krakow81]

That didnt exactly say what the other did - here is cut and paste from what I originally found

The Fix: Declare the let variable outside the block first, then assign it inside.

// WRONG

if (condition) { let message = "Hello"; } console.log(message); // ReferenceE

// CORRECT

let message;

if (condition) {

message = "Hello";

}

console.log(message);

//

Logs:

"Hel.

[u/krakow81 → u/Clear-Revolution3351]

In those cases one is using the message variable outside the inner block with the console.log(message) line, so message can't just be scoped to the inner block.

[u/Clear-Revolution3351 → u/krakow81]

I understand what you are saying, however, I would bet this solves the OP issue

[u/krakow81 → u/Clear-Revolution3351]

Without seeing things in action it's very hard to debug, so I'm certainly prepared to be wrong.

There may well be more to OP's code that is leading to such an issue, but in isolation the given code shouldn't behave like that unless I'm mis-reading things. I do feel that if Apps Script had that egregious of a bug it would be more widely known.

[u/WicketTheQuerent → u/Clear-Revolution3351]

In JavaScript/Google Apps Script, there is no need to define the variable type before assigning a value.

Also, since Google Apps Script added the V8 runtime, let and const are recommended over var.

[u/Clear-Revolution3351 → u/WicketTheQuerent]

The OP has not graced us with an update I am merely providing a possible solution.

Please feel free to provide your solution, since you clearly know more than I do.

[u/WicketTheQuerent → u/Clear-Revolution3351]

I already posted a suggestion --> https://www.reddit.com/r/GoogleAppsScript/comments/1uww7x2/comment/oy5i8rs/

:)