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) 
  ...
end

Is the

Answer 1

if (discount||0) != 0
  #...
end

Answer 2

unless [nil, 0].include?(discount) 
  # ...
end

Answer 3

if discount.nil? || discount == 0
  [do something]
end

Answer 4

if discount and discount != 0
  ..
end

update, it will false for discount = false

Answer 5

I prefer using a more cleaner approach :

val.to_i.zero?

val.to_i will return a 0 if val is a nil,

after that, all we need to do is check whether the final value is a zero.

Answer 6

When dealing with a database record, I like to initialize all empty values with 0, using the migration helper:

add_column :products, :price, :integer, default: 0