Checking if a variable is not nil and not zero in Ruby?

Question

I am using the following code to check if a variable is not nil and not zero if(discount != nil && discount != 0) ... endIs there a better way to do this?

Answer 1

The code you have written is perfectly fine because it is both correct and easy to understand when read.

There are alternate ways to express the same logic, of course. Ruby has .nil? and .zero? methods so you could do this:

if !discount.nil? && !discount.zero?

If you really want to "code golf" this, you could use Ruby's safe navigation operator &. (which automatically checks for nil before calling a method) and Ruby's nonzero? method to get this:

if discount&.nonzero?

And here you can try it out yourself to see that it's correct:

def apply_discount(discount)

if discount&.nonzero?

puts "applying discount"

else

puts "no discount to apply"

end

end

apply_discount(nil)

apply_discount(0)

apply_discount(9)