Check if folder exists in EITHER parent folder, else create - google-apps-script

Question

I have two parent folders that I want to check if Folder(folderName) exists in. folderName is defined by the range S2:2 in my spreadsheet
If Folder(folderName) does not exist in EITHER parent folder, then I want that folder to be created in Parent Folder 1.
So far my script is managing to check Parent Folder 1 and create in Parent Folder 1, but is not checking Parent Folder 2.
This is the script I have so far:
function myfunction() {
var parent = DriveApp.getFolderById("parent Folder 1")
SpreadsheetApp.getActive().getSheetByName('Letter History').getRange('S2:S').getValues()
.forEach(function (r) {
if(r[0]) checkIfFolderExistElsesCreate(parent, r[0]);
})
}
function checkIfFolderExistsElseCreate(parent, folderName) {
var folder;
try {
folder = parent.getFoldersByName(folderName).next();
} catch (e) {
folder = parent.createFolder(folderName);
}

Answer 1

function myFunction() {
var parentFolder1 = DriveApp.getFolderById('<ParentFolder1 ID>').getFolders(); //Get ID for Folder 1
var parentFolder2 = DriveApp.getFolderById('<ParentFolder2 ID>').getFolders(); //Get ID for Folder 2
var sheet = SpreadsheetApp.getActive().getSheetByName('Letter History');
//Iterating to read all the subfolders in ParentFolder 1 and 2
var childNames = [];
while (parentFolder1.hasNext()) {
var child = parentFolder1.next();
childNames.push([child.getName()]);
}
while (parentFolder2.hasNext()) {
var child = parentFolder2.next();
childNames.push([child.getName()]);
}
//Checking if the subfolder/s is existing or not, then creating in folder 1 if not yet existing
var data = sheet.getRange(2, 19, sheet.getLastRow() - 1, 1).getValues(); //S = 19, Change 19 according to column.
for (var i = 0; i < data.length; i++) {
if (childNames.flat().includes(data[i][0])) {
console.log(data[i][0] + "- already exist")
} else {
DriveApp.getFolderById('<ParentFolder1 ID>').createFolder(data[i][0])
console.log(data[i][0] + "- has been created")
}
};
}
The above code will create subfolder/s in Folder 1 based on range S2:S column in spreadsheet, if it is checked that the subfolder name does not yet exist either in Parent Folder 1 or 2.
Please take note to change the following:
ParentFolder 1 ID
ParentFolder 2 ID
Reference: How to create a folder if it doesn't exist?

Answer 2

I believe your goal is as follows.
You want to expand your showing script for using 2 parent folders.
In this case, how about the following sample script?
Sample script:
Please set your parent folder IDs to parentFolderIDs and save the script.
function myfunction() {
// Please set your parent folder IDs you want to use.
const parentFolderIDs = ["###parent folder ID1###", "###parent folder ID2###"];
// 1. Retrieve subfolders from folders of parentFolderIDs.
const parentFolders = parentFolderIDs.map(id => DriveApp.getFolderById(id));
const subFolders = parentFolders.map(folder => {
const temp = [];
const folders = folder.getFolders();
while (folders.hasNext()) {
temp.push(folders.next().getName());
}
return { parent: folder, subFolderNames: temp };
});
// 2. Create new folders when the folder names are not existing.
const sheet = SpreadsheetApp.getActive().getSheetByName('Letter History');
const values = sheet.getRange('S2:S' + sheet.getLastRow()).getDisplayValues();
values.forEach(([s]) => {
if (s) {
subFolders.forEach(({ parent, subFolderNames }) => {
if (!subFolderNames.includes(s)) {
parent.createFolder(s);
}
});
}
});
}
When this script is run, the subfolders in parentFolderIDs are retrieved. And, using the retrieved subfolders, the new subfolders are created in the parent folders of parentFolderIDs.
References:
map()
forEach()