histogram = Hash.new(0) ##給hash表設(shè)置默然值為0
histogram['key1']
histogram['key1'] = histogram['key1'] + 1
histogram['key1']
######################################
##gets 從命令行出入的文件名得到的文件的每一行文本。
while line = gets
puts line.downcase ##downcase全部轉(zhuǎn)換成小寫
end