adding timestamp on three google sheets onedit with Google Apps Script - google-apps-script

Question

I am adding timestamp in col a if colb is edited on 3 sheets.
I have the trigger working onEdit and the information will be updated automatically. It works fine for one, but for 3 im getting an error and cannot run the script.
Is there a simpler way to look for edit in column b in three sheets than what I am doing?
function onEdit() {
var s = SpreadsheetApp.getActiveSheet();
if (s.getName() == "Igualdad Op Hom Mu") {
var r = s.getActiveCell();
if (r.getColumn() == 2) {
var nextCell = r.offset(0, -1);
if (nextCell.getValue() === '')
nextCell.setValue(new Date());
var s2 = SpreadsheetApp.getActiveSheet();
if (s2.getName() == "Incl Per Disc") {
var r2 = s2.getActiveCell();
if (r2.getColumn() == 2) {
var nextCell2 = r2.offset(0, -1);
if (nextCell2.getValue() === '')
nextCell2.setValue(new Date());
var s3 = SpreadsheetApp.getActiveSheet();
if (s3.getName() == "Empr y Col") {
var r3 = s3.getActiveCell();
if (r3.getColumn() == 2) {
var nextCell3 = r3.offset(0, -1);
if (nextCell3.getValue() === '')
nextCell3.setValue(new Date());
}
}
}
}
}
}
}

Answer 1

Try this:
function onEdit(e) {
const sh=e.range.getSheet();
const shts=['Igualdad Op Hom Mu','Incl Per Disc','Empr y Col']
if( shts.indexOf(sh.getName())!=-1 && e.range.columnStart==2) {
const ts=Utilities.formatDate(new Date,Session.getScriptTimeZone(),"yyyy/MM/dd HH:mm:ss");//time stamp
const rg=e.range.offset(0,-1);//next cell to the left
if(rg.getValue()=='') {
rg.setValue(ts);
}
}
}
This function requires the onedit trigger event object so you cannot run this script from the script editor unless you supply the event object.