js验证：密码只能为大写字母+小写字母+数字的8至15位字符组合

var reg = /^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])[a-zA-Z0-9]{8,15}$/ reg = /^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9