How to Validate Email Addresses to Exclude Certain Domains in JavaScript

This guide provides a comprehensive guide to validating email addresses in JavaScript to ensure they do not contain specific domains such as "usa" or "can."
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How to Validate Email Addresses to Exclude Certain Domains in JavaScript

When dealing with email validation in web applications, you might encounter scenarios where you want to restrict certain domains. For example, you may want to check if an email address does not contain "usa" or "can" after the @ symbol. In this post, we will walk through the steps to achieve this using JavaScript, making your email validation processes more robust.

The Problem

You want to validate email addresses to ensure they do not include specific words after the @ symbol. For instance, if a user enters an email like name@ domain.usa, you need to show an error message indicating that this domain is not allowed. As noted in a recent question, using indexOf can lead to confusion and incorrect results. Therefore, we need a clear method to handle the validation properly.

The Basic Approach

Step 1: Extract the Domain

First, we need to isolate the domain of the email address. This is done by locating the @ symbol and taking everything after it. Here's a simple way to achieve that:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Check for Invalid Domains

Next, we want to check if the extracted domain contains any of the restricted words, such as "usa" or "can". Instead of using indexOf, we can use the more straightforward includes method inside a loop. Here’s how to implement that:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Combine Everything

Finally, you can execute the validation function to display an error message if needed. Here’s the complete example:

[[See Video to Reveal this Text or Code Snippet]]

How It Works

The emailValid function accepts an email and an array of restricted words.

It isolates the part of the email after the @ symbol and checks if it contains any of the restricted words.

The function returns false if any restricted word is found; otherwise, it returns true.

Conclusion

By implementing the above code, you can easily validate email addresses and ensure they do not contain unwanted domains. This technique can prevent issues related to domain-specific business logic, enhancing the reliability of your application. With this guide, you are now equipped to handle email validation effectively in JavaScript.

If you have any questions or need further assistance, feel free to leave a comment below!

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