Google表格脚本getLastRow

在以下脚本中，找到spesific列的最后一行：

function GetLastColumn() 
{
   var Col="A"; //Column that will find the last row not empty, can be assigned as parameter
   var sheet = SpreadsheetApp.getActive().getSheetByName('Sheet2');
   var yourRange = sheet.getRange(Col + 1).offset(sheet.getLastRow()-1, 0); //+1 spare 1 row after last row
   var rsltRange = yourRange.getNextDataCell(SpreadsheetApp.Direction.UP);       
   Logger.log(rsltRange.getA1Notation());
};