正则表达式的一些匹配规则
/^\w+([-+.]\w+)*@\w+([-+.]\w+)*\.\w+([-+.]\w+)*$/ email第一种
/^[a-z0-9_+.-]+\@([a-z0-9-]+\.)+[a-z0-9]{2,4}$/ email第二种
/^\d{2}\/\d{2}\/\d{2,4}$/date
/^https?:\/\/([a-z0-9-]+\.)+[a-z0-9]{2,4}.*$/url
/^[a-zA-Z0-9][-a-zA-Z0-9]{0,62}(\.[a-zA-Z0-9][-a-zA-Z0-9]{0,62})+\/?$/ url
/^((25[0-5])|(2[0-4]\d)|(1\d\d)|([1-9]\d)|\d)(\.((25[0-5])|(2[0-4]\d)|(1\d\d)|([1-9]\d)|\d)){3}$/ ip
