vue实现请再次输入密码的表单校验

1、获取第一次输入的密码的值

2、比较两次密码的值是否相等

3、如果不一致返回错误信息

this.userInfo.password2：获取第一次输入的密码；value当前校验值；validator自定义校验规则；
const ConfirmPassword = (rule, value, callback) => {
   if (value !== this.userInfo.password2) {
     callback(new Error('两次输入密码不一致!'))
   } else {
    callback()
   }
}

userInfo: {
     username: '',
     password2: '',
     password3: ''
   },
   rules: {
     username: [{ required: true, message: '请输入用户名', trigger: 'blur' }],
     password2: [{ required: true, message: '请输入密码', trigger: 'blur' }, 
                 { min: 6, max: 9, message: '密码长度6-9位', trigger: 'blur'}],
     password3: [{ required: true, message: '确认密码不能为空', trigger: 'blur' },
                 { trigger: 'blur', validator: ConfirmPassword }]
   }