sortSheets.gs

//3. sort sheets alphabetically
function sortSheets() {
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var sheets = spreadsheet.getSheets();
  var sheetNames = [];
  sheets.forEach(function(sheet,i) {
    sheetNames.push(sheet.getName());
  });
  sheetNames.sort().forEach(function(sheet,i) {
    spreadsheet.getSheetByName(sheet).activate();
    spreadsheet.moveActiveSheet(i + 1);
  });
};