Numbers, strings, symbols, and other types of data are objects belonging to various classes.
Numbers belong to Fixnum, Bignum, Float, and/or Integer classes.
Strings are objects of the String class.
Symbols are objects of the Symbol class.
You can convert objects between the different classes, so a number can become a string and a string can become a number.
puts "12" + "10" puts 12 + 10 # from w w w .j a v a2 s . c om puts "12".to_i + "10".to_i puts 12.to_s + 10.to_s