IE 11 Script1002 Syntax Filter Error

Question

Hi, I get an error in ie11 but not in chrome. Script1002 error. Syntax error

My code is as follows

vm.NoOftroopMemEditReq = (vm.EventAttendees.TicketAttendees.filter(a => a.Attendees.some(Attendee => Attendee.IsEditRequired === true))).length; 

Answer 1

in IE 11 this symbol => does not work, replace => with ===

  vm.NoOftroopMemEditReq = (vm.EventAttendees.TicketAttendees.filter(function (a) { return a.Attendees.some(Attendee === Attendee.IsEditRequired === true); })).length;