ary = Array.new
ary[7] = true
i = 0
while i < ary.length
    v = ary[i]
    puts 'while ...  end: ary[' + i.to_s + '] = ' + v.to_s
    i += 1
end
ary.each_with_index do |v, i|
    puts 'each_with_index:ary[' + i.to_s + '] = ' + v.to_s
end
p ary