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JavaScript

Posted by trottly
trottly
5,394 Points

Event Listeners: Parameter for Event Object in Handler Functions

There's a bit of confusion for me around how the browser knows to insert the event object into the event parameter within a handler function if that parameter may be named whatever you'd like (other than event, evt, or e).

For example: If I were to choose to name the parameter (for the event-object argument) as banana, but also had other unique parameters for the handler function, then how would it know which parameter was meant to receive the event-object argument?

It's definitely useful to have something like e.target to single out whatever element has just been interacted with, but the parameter part is very much confusing me.

1 Answer

Peter Vann
Peter Vann
36,427 Points

I'm led to believe the event object can be named anything you want (although e or event are logical and probably best-practice) and that the first argument will always be the event object (in the addListener callback function).

More info:

https://stackoverflow.com/questions/35936365/what-exactly-is-the-parameter-e-event-and-why-pass-it-to-javascript-functions

I hope that helps.

Stay safe and happy coding!