google sheet scripts get last row with data code example

Example: google script last row

var cells = sheetInput.getRange("a:a").getValues();//Gets all cells in col A.
   
    var filter = cells.filter((cell) => cell != "");//filters out the blanks.
    var lr = parseInt(filter.length) + 1;//This is the Last Row.
    
    Logger.log(lr);