Ruby tips

gistfile1.txt

nil.nil? => true
"".nil? => false

nil.blank? => true
"".blank? => true
[].blank? => true
{}.blank? => true
[1,2].blank? => false
true.blank? => false
false.blank? => true

nil.present? => false
"".present? => false
[].present? => false
{}.present? => false
[1,2].present? => true
true.present? => true
false.present? => false

"".empty? => true
[].empty? => true
[1,2].empty? => false
nil.empty? => NoMethodError: undefined method `empty?' for nil:NilClass