How can set default value for nill or empty string?

[nvtin]

We usually do:

 if input = nil
 value = input || 'default'
 => value = 'default'

But if input is not nil, it is empty string: input = ''

 if input = ''
 value = input || 'default'
 => value = ''

How can we set default value for empty string ?

1. we can use if like:

value = input.present? ? input : 'default'

2. Another way to do it without if.
   Rails adds presence method to all object that does exactly what you want
   See below to use presence:

input = ''
value = input.presence || "default"
=> "default"

input = 'value'
value = input.presence || "default"
=> "value"

input = nil
value = input.presence || "default"
=> "default"

^_^