iterator

~/lang/ruby[372]$ cat list.rb
list = ["a", "b", "c", "d"] ;

for i in 0..3
print i+1, "番目の要素は ", list[i], " です。\n" ;
end


~/lang/ruby[373]$ cat sum_list.rb

list = [1,3,5,7,9] ;
sum = 0 ;

for i in 0..4
sum += list[i] ;
end

print "合計＝", sum, "\n" ;

~/lang/ruby[374]$ cat sum_list2.rb

list = [1,3,5,7,9] ;
sum = 0 ;

list.each{ |elem|
sum += elem ;
}

print "合計＝", sum, "\n" ;

~/lang/ruby[375]$ cat list2.rb

list = ["a", "b", "c", "d"] ;

list.each_with_index { |elem, i|
print i+1, "番目の要素は ", elem, " です。\n" ;
}