Converting `false` into `nil`

Question

When you want to convert a varible v into false when it is nil/false and true otherwise, there is an easy way to do it:

!!v

But is there an easy way to convert v into nil when it is nil/false and retain its value otherwise?

Answer 1

You can use ||=:

a = 'hello'
a ||= nil #=> "hello"

a = true
a ||= nil #=> true

a = false
a ||= nil #=> nil

a = nil
a ||= nil #=> nil