How to check if parameters are empty in rails?

Question

Ruby on Rails

Tried to check like this

p=params.require(:recovery_password).permit(:email)
if p.nil?

However, just before the check, the application crashes with an error that the parameter is empty, on the first line of the example above.
How to check that?
I know it's a simple question, but I can't find it. What matters is how to do it right.

Answer 1

if p.blank?

Answer 2

foo = bar if bar
or
if defined?(bar)
foo = bar