perl 中一个随机编故事的程序（rand函数的应用举例）+好的程序本身就是注释
use strict;use warnings;#定义变量my $count;my $input;my $number;my $sentence;my $story;#定义四个数组#定义了人物数组my @nouns=('Dad','TV','Mom','Groucho','Rebecca','Harpo','Robin Hood','Joe and Moe',);#定义了动作数组my @verbs=('ran to','giggled with','put hot sauce into the orange juice of','exploded','dissolved','dissolved','sang stupid songs with','jumped with',);#定义了地点数组my @prepositions=('at the store','over the rainbow','at the beach','before dinner','in New York City','in a dream','around the world',);do {#每次运行以前，清空$story的内容$story='';#以下是随机组合生成故事for ($count =0;$count<6;$count++){#我们划分一下结构，scalar @nouns 是获取@nouns数组元素的个数，然后用rand总这几个数中随机生成几个，最后int是将得到的数取整$sentence =$nouns[int(rand(scalar @nouns))]." ".$verbs[int(rand(scalar @verbs))]." ".$nouns[int(rand(scalar @nouns))]." ".$prepositions[int(rand(scalar @prepositions))].'.';$story .=$sentence;}print "\n",$story,"\n";print "\nType \"quit\"to quit, or press Enter to continue:";$input=<STDIN>;}#这里是利用正则表达式来匹配首字符是q的字符串，如果有，那么就退出，/^是匹配起始位置，/i是不区分大小写until ($input=~/^\s*q/i);exit;