how to use case and when ruby code example

Example 1: ruby case

case grade
when 'A'
  puts "Way to go kiddo"
when 'B'
  puts "Better luck next time"
when 'C'
  puts "You can do better"
when 'D'
  puts "Scraping through"
when 'F'
  puts "You failed!"
else
  puts "Alternative grading system, eh?"
end

# with ranges
grade = 82
case grade
    when 90..100
      puts "Hooray!"
    when 80...90
      puts "OK job" 
    else
      puts "You failed!"
end

#=> "OK job"

Example 2: ruby case

case fruit
when 'Apple' 
  # something
when 'Banana' then puts 'Right' # only if it is one line
else #default
  # something
end