Ruby program to search a string in a sentence

Write a Ruby program to search a string in a sentence.

class CountStringInSentence
  def countOccurance
     print "Enter the main sentence: "
     main_string = gets.chomp
     print "Enter the search string: "
     search_string = gets.chomp
     count = 0
     main_string.split(" ").each do |s|
       count = count + 1 if s.casecmp(search_string).zero?
     end
     print "search string '#{search_string}' occured #{count} times"
  end
end

p = CountStringInSentence.new 
p.countOccurance

Output:

Enter the main sentence:  samajh samajh ke samajh ko samjho
Enter the search string:  samajh
search string 'samajh' occured 3 times