How to delete all rows except the last 2 from a google sheet using a Script?

Question

I need to delete all rows except the last 2 from a google sheet. The number of rows can vary. But I need always the last 2 rows.

How should be the script to do this?

Answer 1

In regards to your comment on the other answer, perhaps this will help you.

function myfunc101() {
  const ss = SpreadsheetApp.getActive();
  const sh = ss.getSheetByName('DailyHelpDesk');
  const sr = 2;//data start row
  const nr = 2;//number of rows to leave at the bottom
  const rg = sh.getRange(sr, 1, sh.getLastRow() - sr - nr + 1,sh.getLastColumn());
  sh.deleteRow(sr,rg.getNumRows());
}

Answer 2

// getting sheet to work on
var sheet = SpreadsheetApp.getActive().getSheetByName(<sheet name goes here>);

start = 1; // Hard coded row number from where to start deleting
howManyToDelete = sheet.getLastRow() - 2; // Leaving the last two rows

sheet.deleteRows(start, howManyToDelete);