常用正则表达式

1、邮件校验

emailRegex = /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/

2、用户名校验
Username may consist of a-z, 0-9, underscores, spaces and must begin with a letter.

/^[a-z]([0-9a-z_\s])+$/i

3、密码校验
Password field only allow : a-z 0-9

/^([0-9a-zA-Z])+$/