List names of sheets in Google Sheets - google-sheets

Question

I found code to list the names of all the sheets in Google Sheets
function sheetnames() {
var out = new Array()
var sheets = SpreadsheetApp.getActiveSpreadsheet().getSheets()
for (var i=2 ; i<sheets.length ; i++) out.push( [ sheets[i].getName() ] )
return out
}
But we must place =sheetnames() in a cell to get value.
Is there any improvement in the script to automatically update when creating a new sheet?

Answer 1

You have to install an onChange trigger, which runs a function whenever a user modifies the structure of the spreadsheet—for example, when a sheet is inserted or removed.
You can install the trigger manually, following these steps, or programmatically, executing this function once:
function createOnChangeTrigger() {
const ss = SpreadsheetApp.getActive();
ScriptApp.newTrigger("writeSheetNames")
.forSpreadsheet(ss)
.onChange()
.create();
}
Once this is installed, the function writeSheetNames will run every time a sheet is created, removed, or renamed. This function should do two things:
Retrieve the sheet names of all the sheets in the spreadsheet.
Write these sheet names to the cell you indicate.
For example, the function below would write the data to column A of the sheet named Sheet1.
Code sample:
function writeSheetNames() {
const ss = SpreadsheetApp.getActive();
const sheetNames = ss.getSheets().map(sheet => [sheet.getName()]);
const sheet = ss.getSheetByName("Sheet1");
sheet.getRange("A:A").clear(); // Delete previous data
sheet.getRange(1,1,sheetNames.length).setValues(sheetNames);
}
Reference:
onChange