Home Web Front-end JS Tutorial How to verify the correct email address in JS

How to verify the correct email address in JS

Apr 28, 2018 am 09:35 AM
javascript verify

This time I will show you how to verify the correct email address in JS. What are the precautions for verifying the correct email address in JS? The following is a practical case, let's take a look.

I recently worked on a front-end project, which requires that the input data must contain the @ symbol and the period (.). At the same time, @ cannot be the first character of the email address, and there must be at least one period after @.

1: Code

nbsp;html>


<meta>
<title>利用JavaScript验证是否符合电子邮箱地址</title>

<script>
  // 创建第一个函数validate_emil()并包含两个参数
  function validate_email(field, alerttxt) {
    with (field) {
      //利用indexOf() 方法返回某个指定的字符串值在字符串中首次出现的位置--定义一个变量apos将第一次出现的“@”赋值给apos
      apos = value.indexOf("@");
      //利用lastIndexOf() 方法返回一个指定的字符串值最后出现的位置,在一个字符串中的指定位置从后向前搜索--
      //stringObject.lastIndexOf(searchvalue,fromindex)
      //fromindex 可选的整数参数。规定在字符串中开始检索的位置。它的合法取值是 0 到 stringObject.length - 1。如省略该参数,则将从字符串的最后一个字符处开始检索。
      dotpos = value.lastIndexOf(".");
      // 判断符合"@"的位置,或者"."的位置是否在"@"的后面
      if (apos < 1 || dotpos - apos < 2) {
        // 利用alert()弹出一个警告窗来执行alerttxt的操作
        // 邮箱地址不符合
        alert(alerttxt);
        return false;
      } else {
        // 邮箱地址符合
        return true;
      }
    }
  }
  // 创建第二个函数validate_form()并包含一个参数
  function validate_form(thisform) {
    with (thisform) {
      if (validate_email(email, "Not a valid e-mail address!") == false) {
        // 利用focus()将输入焦点移至对象上
        email.focus();
        return false;
      }
    }
  }
</script>

  <!-- onsubmit是一个验证表单功能,为true提交, -->
  
Copy after login
    Email:     

2: Result

How to verify the correct email address in JS

The following picture explains The email format you entered is accurate, whether it exists or not is another matter!

How to verify the correct email address in JS

# I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Recommended reading:

controller receives js and passes json parameters

js implements front-end and back-end Json transmission to each other

The above is the detailed content of How to verify the correct email address in JS. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to verify signature in PDF How to verify signature in PDF Feb 18, 2024 pm 05:33 PM

We usually receive PDF files from the government or other agencies, some with digital signatures. After verifying the signature, we see the SignatureValid message and a green check mark. If the signature is not verified, the validity is unknown. Verifying signatures is important, let’s see how to do it in PDF. How to Verify Signatures in PDF Verifying signatures in PDF format makes it more trustworthy and the document more likely to be accepted. You can verify signatures in PDF documents in the following ways. Open the PDF in Adobe Reader Right-click the signature and select Show Signature Properties Click the Show Signer Certificate button Add the signature to the Trusted Certificates list from the Trust tab Click Verify Signature to complete the verification Let

Detailed method to unblock using WeChat friend-assisted verification Detailed method to unblock using WeChat friend-assisted verification Mar 25, 2024 pm 01:26 PM

1. After opening WeChat, click the search icon, enter WeChat team, and click the service below to enter. 2. After entering, click the self-service tool option in the lower left corner. 3. After clicking, in the options above, click the option of unblocking/appealing for auxiliary verification.

How to implement an online speech recognition system using WebSocket and JavaScript How to implement an online speech recognition system using WebSocket and JavaScript Dec 17, 2023 pm 02:54 PM

How to use WebSocket and JavaScript to implement an online speech recognition system Introduction: With the continuous development of technology, speech recognition technology has become an important part of the field of artificial intelligence. The online speech recognition system based on WebSocket and JavaScript has the characteristics of low latency, real-time and cross-platform, and has become a widely used solution. This article will introduce how to use WebSocket and JavaScript to implement an online speech recognition system.

WebSocket and JavaScript: key technologies for implementing real-time monitoring systems WebSocket and JavaScript: key technologies for implementing real-time monitoring systems Dec 17, 2023 pm 05:30 PM

WebSocket and JavaScript: Key technologies for realizing real-time monitoring systems Introduction: With the rapid development of Internet technology, real-time monitoring systems have been widely used in various fields. One of the key technologies to achieve real-time monitoring is the combination of WebSocket and JavaScript. This article will introduce the application of WebSocket and JavaScript in real-time monitoring systems, give code examples, and explain their implementation principles in detail. 1. WebSocket technology

How to use JavaScript and WebSocket to implement a real-time online ordering system How to use JavaScript and WebSocket to implement a real-time online ordering system Dec 17, 2023 pm 12:09 PM

Introduction to how to use JavaScript and WebSocket to implement a real-time online ordering system: With the popularity of the Internet and the advancement of technology, more and more restaurants have begun to provide online ordering services. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects dishes and places an order

New features in PHP 8: Added verification and signing New features in PHP 8: Added verification and signing Mar 27, 2024 am 08:21 AM

PHP8 is the latest version of PHP, bringing more convenience and functionality to programmers. This version has a special focus on security and performance, and one of the noteworthy new features is the addition of verification and signing capabilities. In this article, we'll take a closer look at these new features and their uses. Verification and signing are very important security concepts in computer science. They are often used to ensure that the data transmitted is complete and authentic. Verification and signatures become even more important when dealing with online transactions and sensitive information because if someone is able to tamper with the data, it could potentially

How to implement an online reservation system using WebSocket and JavaScript How to implement an online reservation system using WebSocket and JavaScript Dec 17, 2023 am 09:39 AM

How to use WebSocket and JavaScript to implement an online reservation system. In today's digital era, more and more businesses and services need to provide online reservation functions. It is crucial to implement an efficient and real-time online reservation system. This article will introduce how to use WebSocket and JavaScript to implement an online reservation system, and provide specific code examples. 1. What is WebSocket? WebSocket is a full-duplex method on a single TCP connection.

JavaScript and WebSocket: Building an efficient real-time weather forecasting system JavaScript and WebSocket: Building an efficient real-time weather forecasting system Dec 17, 2023 pm 05:13 PM

JavaScript and WebSocket: Building an efficient real-time weather forecast system Introduction: Today, the accuracy of weather forecasts is of great significance to daily life and decision-making. As technology develops, we can provide more accurate and reliable weather forecasts by obtaining weather data in real time. In this article, we will learn how to use JavaScript and WebSocket technology to build an efficient real-time weather forecast system. This article will demonstrate the implementation process through specific code examples. We

See all articles