count how many letter occurrences there are in a string (in ruby)

 Your code is here- 

 

• dna1 = ('ATTGCC')
• W= dna1.count('A')       //letter occurrences  count function
• X= dna1.count('T')
• Y= dna1.count('G')
• Z= dna1.count('C')
• puts "{"+ "'A'=>" + "#{W}"+ "," + "'T'=>" + "#{X}" + "," +"'G'=>" + "#{Y}" +"," + "'C'=>" + "#{Z}" + "}"

screenshot of output-