form.createResponse()returns FormResponsewhich you need to assign to the variable.
also withItemResponse()expects an object of type ItemResponse. I am not familiar with Google forms, but maybe this will help you in the right direction:
var formID = row[24];
var form = FormApp.openById(formID);
var formResponse = form.createResponse();
var items = form.getItems();
for (index = 0; index < a.length; ++index) {
var item = items[index]
if (item.getType() == 'TEXT') {
var textItem = item.asTextItem();
var itemresponse = textItem.createResponse('Core Teachers');
formResponse.withItemResponse(itemresponse);
}
}
formResponse.submit();
, - , , String Boolean, , createResponse. , GoogleAppsScript .