Pangram checker

You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.

For example:   The quick brown fox jumps over the lazy dog.



Task

Write a function or method to check a sentence to see if it is a   pangram   (or not)   and show its use.



Related tasks

   determine if a string has all the same characters
   determine if a string has all unique characters


def pangram?(sentence)
  s = sentence.downcase
  ('a'..'z').all? {|char| s.include? (char) }
end
 
p pangram?('this is a sentence')  # ==> false
p pangram?('The quick brown fox jumps over the lazy dog.')  # ==> true