Ruby/Hash/each

hash = { "key1" => "val1", "key2" => "val2" }
string = ""
hash.each { |k,v| string << "#{k} is #{v}\n" }
puts string

x = { "a" => 1, "b" => 2 }
x.each { |key, value| puts "#{key} equals #{value}" }

transform_results = { 4 => 8, 9 => 9, 10 => 6, 2 => 7, 6 => 5 }
transform_results.each { |x, y| puts "f(#{x})=#{y}: difference #{y-x}" }
# f(9)=9: difference 0
# f(6)=5: difference -1
# f(10)=6: difference -4
# f(4)=8: difference 4
# f(2)=7: difference 5

zip = { 2 => "A", 5 => "T", 3=> "h", 4 => "e", 8 => "T" }
zip.each {|k,v| puts "#{k}/#{v}" } # =>