CustomEventinterface CustomEvent <T = any> extends Event {readonly detail: T;}var CustomEvent: {readonly prototype: CustomEvent; new <T>(typeArg: string, eventInitDict?: CustomEventInit<T>): CustomEvent<T>; };§Type Parameters§T = any[src]§Extends§Event[src]§Properties§readonly detail: T[src]Returns any custom data event was created with. Typically used for synthetic events.