Hi, "Dat Nguyen" <thucdat / hotmail.com> wrote | each_index {...} | (0..ary.size).each {...} The "Range" object samples. ary = ["a", "b", "c"] ary.each {|e| print e, "\n"} puts "" ary.each_index {|i| print i, "\n"} puts "" (0...ary.size).each {|i| print i, "\n"} puts "" (0..ary.size).each {|i| print i, "\n"} puts "" -- ARIMA Yasuhiro <fit0298 / fitec.co.jp>