4 Efficient Ways to validate Email Address in JavaScript

Validating email addresses is an essential task in web development, and JavaScript provides several methods to accomplish this. By using the keyword "javascript validate email," we can specifically discuss the different methods available in JavaScript for email validation.

One common method for validating email addresses in JavaScript is through regular expressions. A regular expression is a sequence of characters that defines a pattern that can be used to check if a given string matches that pattern. For email validation, regular expressions can be used to check the format of an email address and ensure that it follows a specific pattern.

Another approach for email validation in JavaScript is to use pre-built validation libraries that provide pre-defined rules for email validation. These libraries simplify the process of email validation, and they can provide error messages and feedback to the user to correct any issues with the email address.

It is also crucial to perform server-side validation of email addresses to ensure that the data submitted is valid and secure. This can involve performing additional checks, such as checking if the email address is associated with known spam or fraudulent activity.

 

Different methods to validate email address in JavaScript

Here are some different methods to validate email addresses in JavaScript:

1. Regular expressions: Regular expressions can be used to check if an email address matches a specific pattern. This method involves defining a regular expression that matches the desired pattern for email addresses, and then using the test() method to check if a given string matches the pattern.
2. Email validation libraries: There are several third-party libraries available that provide email validation functionality. These libraries can simplify the process of validating email addresses, as they often provide pre-built validation rules and error messages.
3. HTML5 validation: The HTML5 input element includes a type="email" attribute that can be used to validate email addresses in supported browsers. When a user submits a form containing an input element with type="email", the browser will automatically validate the input and display an error message if the email address is not valid.
4. Server-side validation: While JavaScript can be used to validate email addresses on the client-side, it's important to also perform validation on the server-side to ensure that the submitted data is valid and secure. Server-side validation can involve checking the format of the email address, as well as performing additional checks to ensure that the email address is not associated with known spam or fraudulent activity.

 

1. Using Regular Expressions

Regular expressions or RegExp for short is a pattern that allows to match or describe a set of strings. Based on the pattern defined, we can test on whether a string passes or fails the pattern. Since, email addresses are strings and have a specific structure - username, followed by an @ and the domain. Therefore, regular expressions are a powerful tool to validate email addresses.

Here is an example of a regular expression that matches most valid email addresses:

const emailRegex = /^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$/;

The emailRegex variable holds a regular expression that matches email addresses. The regular expression consists of three parts:

• ^[^\\s@]+ matches one or more characters that are not whitespace or '@' at the beginning of the string.
• @[^\\s@]+ matches the '@' symbol followed by one or more characters that are not whitespace or '@'.
• \\.[^\\s@]+$ matches a period (.) followed by one or more characters that are not whitespace or '@' at the end of the string.

To use this regular expression to validate an email address, we can call the test() method on the regex and pass in the email address:

const emailRegex = /^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$/;
const email = "test@gmail.com";
const isValidEmail = emailRegex.test(email);
console.log(isValidEmail);

const emailTwo = "aqdf200@x.";
const isValidEmailTwo = emailRegex.test(emailTwo);
console.log(isValidEmailTwo);

Output

false

The test() method returns true if the email address matches the regular expression, and false otherwise.

 

2. Using HTML5 Validation

Another approach is to use the validation system that comes with every browser via HTML5. It provides a built-in way to validate email addresses using the type attribute of the input element. Here is an example:

<input type="email" name="email" required>

The type attribute is set to "email", which tells the browser to validate the input as an email address. The required attribute makes the input required, so the user must enter a value.

To check if the email address is valid, we can use the checkValidity() method on the input element. For illustrative purposes, we will create a simple HTML page that will accept an email address and submit. Afterwards, an alert message will show true if valid and false if otherwise. We will make use of event listeners.

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Email Validation</title>
    </head>
    <body>
        <input type="email" name="email" required />
        <button id="button" type="submit">Submit</button>
        <script src="script.js"></script>
    </body>
</html>

The script.js file

const button = document.getElementById("button");

button.addEventListener("click", function () {
    const emailInput = document.querySelector('input[name="email"]');
    const isValidEmail = emailInput.checkValidity();
    alert(isValidEmail);
});

Output

The checkValidity() method returns true if the input value is valid, and false otherwise.

 

3. Using Email validation Third-Party Libraries

There are several third-party libraries available that provide email validation. These libraries usually provide a more comprehensive validation algorithm and are frequently updated to match the latest email address specifications. Some popular libraries include:

• validator.js
• email-validator
• mailcheck

To showcase how easy it is to use third-party libraries, we will install the validator library using the npm command below

npm install validator

Afterwards, we can make use of the code below which first imports the validator library then makes use of the isEmail() method to check if the passed argument - email - is a valid email.

let validator = require("validator");

const email = "test@gmail.com";
const isValidEmail = validator.isEmail(email);
console.log(isValidEmail);

Output

true

The isEmail() method from validator.js returns true if the email address is valid, and false otherwise.

 

4. Server-side validation

Server-side validation involves validating user input on the server before processing it. This is important because client-side validation, such as using JavaScript to validate email addresses, can be bypassed by malicious users who may try to submit invalid or malicious data.

Here's an example of server-side validation for email addresses in a Node.js application:

const express = require('express');
const app = express();

app.use(express.json());

app.post('/signup', (req, res) => {
  const { email } = req.body;

  // Perform server-side validation of email address
  if (!isValidEmail(email)) {
    return res.status(400).json({ message: 'Invalid email address' });
  }

  // Process the user's input
  // ...
});

function isValidEmail(email) {
  // Check if the email address is valid
  const emailRegex = /^\S+@\S+\.\S+$/;
  return emailRegex.test(email);
}

In this example, the server receives a POST request containing an email address in the request body. Before processing the request, the server performs server-side validation of the email address by calling the isValidEmail() function, which checks if the email address matches a specific pattern using a regular expression.

If the email address is invalid, the server responds with a 400 Bad Request status code and an error message indicating that the email address is invalid. Otherwise, the server processes the user's input.

 

Summary

Email validation is an important task in web development, and there are several methods available in JavaScript to accomplish this. This article covers four common methods of email validation in JavaScript: using regular expressions, using HTML5 validation, using email validation third-party libraries, and performing server-side validation.

Regular expressions are a powerful and flexible way to validate email addresses in JavaScript. They allow developers to define specific patterns for email addresses and provide a robust solution to ensure the validity of email addresses.

HTML5 validation is another simple and easy way to validate email addresses in supported browsers. This method provides built-in validation rules that can be used to check the format of the email address.

Email validation third-party libraries provide a pre-built solution for email validation. They often include pre-defined validation rules and error messages, simplifying the process of email validation.

Finally, performing server-side validation is essential to ensure the security and validity of user-submitted data. Server-side validation can check the format of email addresses and perform additional checks, such as verifying that the email address is not associated with known spam or fraudulent activity.

 

References

Regular expressions - JavaScript | MDN (mozilla.org)
validatorjs/validator.js: String validation (github.com)