FILTER_VALIDATE_EMAIL constant in PHP

The FILTER_VALIDATE_EMAIL constant is used with PHP's filter_var() function to validate email addresses. It checks if an email follows the standard email format and returns the email if valid, or false if invalid.

Syntax

filter_var($email, FILTER_VALIDATE_EMAIL)

Return Value

Returns the validated email address on success, or false on failure.

Example

Here's how to validate an email address using FILTER_VALIDATE_EMAIL −

<?php
    $myEmail = "example@demo.com";
    
    if (filter_var($myEmail, FILTER_VALIDATE_EMAIL)) {
        echo "$myEmail = valid email address";
    } else {
        echo "$myEmail = invalid email address";
    }
?>

example@demo.com = valid email address

Testing Invalid Emails

Let's test with various invalid email formats −

<?php
    $emails = [
        "valid@example.com",
        "invalid.email",
        "@missinglocal.com",
        "missing@.com",
        "spaces @example.com"
    ];
    
    foreach ($emails as $email) {
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
            echo "$email is VALID<br>";
        } else {
            echo "$email is INVALID<br>";
        }
    }
?>

valid@example.com is VALID
invalid.email is INVALID
@missinglocal.com is INVALID
missing@.com is INVALID
spaces @example.com is INVALID

Conclusion

FILTER_VALIDATE_EMAIL provides a reliable way to validate email addresses in PHP. It returns the email if valid or false if invalid, making it perfect for form validation and data processing.