formreaction.js

function respondToFormSubmit(e) {
  var settings = PropertiesService.getDocumentProperties();
  var authInfo = ScriptApp.getAuthorizationInfo(ScriptApp.AuthMode.FULL);

  // Check if the actions of the trigger require authorizations that have not
  // been supplied yet -- if so, warn the active user via email (if possible).
  // This check is required when using triggers with add-ons to maintain
  // functional triggers.
  if (authInfo.getAuthorizationStatus() ==
      ScriptApp.AuthorizationStatus.REQUIRED) {
    // Re-authorization is required. In this case, the user needs to be alerted
    // that they need to reauthorize; the normal trigger action is not
    // conducted, since authorization needs to be provided first. Send at
    // most one 'Authorization Required' email a day, to avoid spamming users
    // of the add-on.
    sendReauthorizationRequest();
  } else {
    Logger.log("responded to form submit"); 
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var sheet = ss.getSheets()[0];
    
    var values = sheet.getDataRange().getValues()
    Logger.log(values.length) 
    
    for(n=1;n<values.length+1;++n){
      // var cell = values[n][3] ; // x is the index of the column starting from 0
      var coordinate = "G" + n; 
      Logger.log(coordinate);
      var cell = sheet.getRange(coordinate);
      var formulat_string = '=CONCATENATE(B' + n + '," ",' + 'C' + n + ')';  
      cell.setFormula(formulat_string);       
    } 
  }
}