Function and usage of is_email() in wordpress


Answers ( 1 )


    The is_email() function in WordPress is a straightforward utility for verifying the validity of an email address. Here's a detailed breakdown of its usage and functionality:

    Function Signature:

    is_email( string $email, bool $deprecated = false ): string|false

    Function Purpose:

    • Primary Function: To verify whether a given email address is valid.
    • Note on Compliance: It does not support internationalized domain names and is not fully compliant with RFC standards. This means it might not recognize certain valid email formats, especially those with non-ASCII characters in the domain part.


    1. $email (string, required): The email address that needs to be validated.

      • This should be a string representing the email address you want to check.
      • Example: ""
    2. $deprecated (bool, optional): A flag for deprecated functionality.

      • Its default value is false.
      • Historically, this might have been used for backward compatibility or specific checks, but as of now, it doesn't serve a functional purpose in the standard usage of the function.

    Return Values:

    • Success: If the email is valid, the function returns the email address as a string.
    • Failure: If the email is invalid, it returns false.

    Sample Usage:

    Here's an example of how you might use is_email() in a WordPress context:

    $email_to_check = "";
    $validated_email = is_email($email_to_check);
    if ( $validated_email ) {
        echo "Valid email: " . $validated_email;
    } else {
        echo "Invalid email.";

    Practical Considerations:

    • Use Case: This function is often used in form validations, user input sanitization, or anywhere you need to ensure that an email address provided by a user is syntactically correct.
    • Limitations: Since it's not fully RFC compliant and doesn't support internationalized domain names, it may not be suitable for all applications, especially those requiring a broad range of email format support.

    In summary, is_email() is a handy function for basic email validation in WordPress, but its limitations in terms of internationalization and full RFC compliance should be considered when deciding whether it's the right tool for your specific needs.

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