Merge n Google spreadsheets files to n sheets - google-apps-script

Question

Say, I have 100 google spreadsheets file and I need to merge into one file with 100 tabs(sheets). Is it possible with app script. Currently I have a code below,
function popForm() {
var ss = SpreadsheetApp.getActive();
for(var b = 0; b<100; b++){
var sheet = ss.getSheetByName('Sheet '+b);
var numberRows = sheet.getDataRange().getNumRows();
....
....
The above code will work with spreadsheets with 100 tabs(Sheets). But I have 100 sreadsheets with one tab(Sheet).

Answer 1

Explanation:
You have a folder with FolderId that contains all the spreadsheet
files. You find this folder using the getFolderById() method.
You get the files of this folder using the getFiles() method and
you use a while loop to iterate over these files.
For every file, you get the first sheet and you copy it using the
copyTo() method to the source (active) spreadsheet file.
The newly create sheet will be named after the name of the spreadsheet file that it came from. Feel free to change this part or let me know so I can modify it.
Solution:
You must be looking for this:
function myFunction() {
const source_sh = SpreadsheetApp.getActive();
const folder = DriveApp.getFolderById('FolderId');
const files = folder.getFiles();
while (files.hasNext()) {
var file = files.next();
var target_ss = SpreadsheetApp.openById(file.getId());
var target_sh = target_ss.getSheets()[0];
target_sh.copyTo(source_sh).setName(file.getName());
}
}