How to define default value in field type (not in options)

I understand that we can define a default value in the JSON options, but how exactly can we update the “default” value that is part of the field object type? It seems that it always defaults to empty string.

most things you put to the json is reflected onto the fields in the resulting form.

See Collection Field: Email Validation - #2 by serjoscha87 for detailed information

So you could actually try to set the “value” field. But I’m not sure if this could not cause any torubles. But you can give it a try