$ 匹配行结束符.例如正则表达式weasel$ 能够匹配字符串"He's a weasel"的末尾 但是不能匹配字符串"They are a bunch of weasels." ^ 匹配一行的开始.例如正则表达式^When in能够匹配字符串"When in the course of human events"的开始,但是不能匹配"What and When in the" 用这个吧:匹配Email地址的正则表...