Function listenerCount

listenerCount<E extends string | symbol>(
eventName: string | symbol,
listener?: (...args: any[]) => void,
): number
Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.
Type Parameters
- E extends string | symbol
Parameters
- eventName: string | symbol
  The name of the event being listened for
- Optionallistener: (...args: any[]) => void
  The event handler function
Returns number
Since
v3.2.0