Javascript 使用正则表达式进行typescript（ionic2）电子邮件验证

我在使用Typescript验证电子邮件地址是否有效时遇到了问题，使用正则表达式就是这样。
我遇到运行时错误“无法读取未定义的属性'value'”

完整代码

import {Component} from '@angular/core';
import { BackandService } from '@backand/angular2-sdk'
import { LoginPage } from '../login/login';
import { AlertController } from 'ionic-angular';




@Component({
  templateUrl: 'signup.html',
  selector: 'page-signup',
 })

export class SignupPage {

  email:string = '';
  firstName:string = '';
  lastName:string = '';
  signUpPassword: string = '';
  confirmPassword: string = '';
  bloodType: Object = {};



  constructor(private backand: BackandService, private alertCtrl: 
 AlertController) {

  }


  public signUp(email) {

  if(this.email == '' || this.firstName == '' ||  this.lastName == '' ||  this.signUpPassword == '' ||  this.confirmPassword == ''){
  let alert = this.alertCtrl.create({
    title: 'Error ',
    subTitle: 'Must fill in all fields.',
    buttons:['Try Again']
  });
  alert.present();
}


  if(this.signUpPassword != this.confirmPassword){
    let alert = this.alertCtrl.create({
      title: 'Error ',
      subTitle: 'Passwords must match.',
      buttons:['Try Again']
    });
    alert.present();
    }

  if(this.signUpPassword.length < 6 && this.confirmPassword.length < 6){
    let alert = this.alertCtrl.create({
      title: 'Error ',
      subTitle: 'Password must be 6 characters.',
      buttons:['Try Again']
    });
    alert.present();
  }

 var reg = /^([\w-\.]+@(?!lsu.edu)([\w-]+\.)+[\w-]{2,4})?$/
  if (reg.test(email.value) == false) {
    let alert = this.alertCtrl.create({
      title: 'Error ',
      subTitle: 'Invalid email.',
      buttons:['Try Again']
    });
    alert.present();
    return false;
 }


this.backand.signup(this.firstName, this.lastName, this.email, this.signUpPassword, this.confirmPassword, this.bloodType)
.then((res: any) =>
  {
  let alert = this.alertCtrl.create({
    subTitle: 'Thank you for signing up.',
    buttons:['Login']
  });
  alert.present();
    this.email = this.signUpPassword = this.confirmPassword = this.firstName = this.lastName = this.bloodType = '';
  }
);
  }
}

从'@angular/core'导入{Component}；
从'@backand/angular2 sdk'导入{BackandService}
从“../login/login”导入{LoginPage}；
从'ionic angular'导入{AlertController}；
@组成部分({
templateUrl:'signup.html'，
选择器：“页面注册”，
})
导出类签名{
电子邮件：string=''；
firstName:string=''；
lastName:string=''；
signUpPassword:string=''；
confirmPassword:字符串=“”；
血型：对象={}；
构造函数（专用backand:BackandService，专用alertCtrl:
警报控制器）{
}
公开注册（电子邮件）{
如果（this.email=''this.firstName=''this.lastName=''this.signUpPassword=''this.confirmPassword=''）{
让alert=this.alertCtrl.create({
标题：“错误”，
副标题：“必须填写所有字段。”，
按钮：[“重试”]
});
alert.present（）；
}
if（this.signUpPassword！=this.confirmPassword）{
让alert=this.alertCtrl.create({
标题：“错误”，
副标题：“密码必须匹配。”，
按钮：[“重试”]
});
alert.present（）；
}
if（this.signUpPassword.length<6&&this.confirmPassword.length<6）{
让alert=this.alertCtrl.create({
标题：“错误”，
副标题：“密码必须为6个字符。”，
按钮：[“重试”]
});
alert.present（）；
}
var reg=/^（[\w-\.]+@（？！lsu.edu）（[\w-]+\.+[\w-]{2,4}）$/
if（注册测试（email.value）==false）{
让alert=this.alertCtrl.create({
标题：“错误”，
副标题：“无效电子邮件”，
按钮：[“重试”]
});
alert.present（）；
返回false；
}
this.backand.signup（this.firstName、this.lastName、this.email、this.signUpPassword、this.confirmPassword、this.bloodType）
。然后（（res:any）=>
{
让alert=this.alertCtrl.create({
副标题：“感谢您的注册。”，
按钮：[“登录”]
});
alert.present（）；
this.email=this.signUpPassword=this.confirmPassword=this.firstName=this.lastName=this.bloodType=''；
}
);
}
}

您遇到了什么问题？我遇到了一个运行时错误“无法读取未定义的属性‘值’”。这意味着您的

电子邮件

未定义。这个错误与正则表达式无关。问题在于代码调用

signup（）

。您的正则表达式匹配的

--@

不是有效的电子邮件地址。它抱怨

email

参数

未定义（因此您无法调用
email.value
）。解释调用函数的方式和位置。
import {Component} from '@angular/core';
import { BackandService } from '@backand/angular2-sdk'
import { LoginPage } from '../login/login';
import { AlertController } from 'ionic-angular';




@Component({
  templateUrl: 'signup.html',
  selector: 'page-signup',
 })

export class SignupPage {

  email:string = '';
  firstName:string = '';
  lastName:string = '';
  signUpPassword: string = '';
  confirmPassword: string = '';
  bloodType: Object = {};



  constructor(private backand: BackandService, private alertCtrl: 
 AlertController) {

  }


  public signUp(email) {

  if(this.email == '' || this.firstName == '' ||  this.lastName == '' ||  this.signUpPassword == '' ||  this.confirmPassword == ''){
  let alert = this.alertCtrl.create({
    title: 'Error ',
    subTitle: 'Must fill in all fields.',
    buttons:['Try Again']
  });
  alert.present();
}


  if(this.signUpPassword != this.confirmPassword){
    let alert = this.alertCtrl.create({
      title: 'Error ',
      subTitle: 'Passwords must match.',
      buttons:['Try Again']
    });
    alert.present();
    }

  if(this.signUpPassword.length < 6 && this.confirmPassword.length < 6){
    let alert = this.alertCtrl.create({
      title: 'Error ',
      subTitle: 'Password must be 6 characters.',
      buttons:['Try Again']
    });
    alert.present();
  }

 var reg = /^([\w-\.]+@(?!lsu.edu)([\w-]+\.)+[\w-]{2,4})?$/
  if (reg.test(email.value) == false) {
    let alert = this.alertCtrl.create({
      title: 'Error ',
      subTitle: 'Invalid email.',
      buttons:['Try Again']
    });
    alert.present();
    return false;
 }


this.backand.signup(this.firstName, this.lastName, this.email, this.signUpPassword, this.confirmPassword, this.bloodType)
.then((res: any) =>
  {
  let alert = this.alertCtrl.create({
    subTitle: 'Thank you for signing up.',
    buttons:['Login']
  });
  alert.present();
    this.email = this.signUpPassword = this.confirmPassword = this.firstName = this.lastName = this.bloodType = '';
  }
);
  }
}