Hey everyone,
I'm trying to validate an email address in PHP using `filter_var()`. I want to check if a string entered by the user is a valid email address or not. Can somebody provide me with a PHP program that does this using the `filter_var()` function?
I have recently started working on a project where user input validation is crucial. I need to ensure that only valid email addresses are accepted. I heard that the `filter_var()` function in PHP can be very helpful for this purpose. I would really appreciate it if someone could share a sample PHP program that demonstrates how to use `filter_var()` to check if a string is a valid email address.
I have read the PHP manual regarding `filter_var()`, but I'm still a bit confused about the exact implementation. It would be great if you could also explain how the different flags can be used with `filter_var()` to achieve different validations, such as filtering out email address domains that don't exist.
Thank you so much in advance!

Hey there,
I'm thrilled to share my experience with you on using `filter_var()` for validating email addresses in PHP!
In my recent project, I had to implement email address validation, and I found `filter_var()` to be a handy function for the job. Here's an example code snippet that demonstrates how it can be used:
By passing the email string and the `FILTER_VALIDATE_EMAIL` flag to `filter_var()`, you can easily check whether the entered email address is valid or not. In our example above, if the email address is valid, you'll see the message "Great news! The email address is valid!" displayed. Otherwise, it will show "Oops! The email address is invalid."
Regarding filtering email addresses with non-existent domains, unfortunately, `filter_var()` alone cannot handle that. You'd need to explore other methods, such as performing a manual DNS check or utilizing third-party libraries that offer advanced email validation capabilities.
In my case, I opted to use the "egulias/email-validator" library in combination with `filter_var()`. This library provides an extensive range of email validation features including domain existence and MX record checks. This combination allowed me to ensure the email addresses entered by users were both properly formatted and linked to valid domains.
I hope this insight from my experience is helpful to you. If you have any more questions or need further assistance, feel free to ask!