PHP Exercises : Email validation

Last update on April 19 2025 11:49:48 (UTC/GMT +8 hours)

12. Email Validation

Write a simple PHP program to check that emails are valid.

Hints : Use FILTER_VALIDATE_EMAIL filter that validates value as an e-mail address.
Note : The PHP documentation does not say that FILTER_VALIDATE_EMAIL should pass the RFC5321.

Sample Solution:

PHP Code:

<?php
// Specify an email address (valid or invalid)
$email = "[email protected]";

// Use the filter_var function with FILTER_VALIDATE_EMAIL to check if the email is valid
if (filter_var($email, FILTER_VALIDATE_EMAIL)) 
{
    // If the email is valid, print a message indicating it is valid
    echo '"' . $email . '" = Valid'."\n";
}
else 
{
    // If the email is invalid, print a message indicating it is invalid
    echo '"' . $email . '" = Invalid'."\n";
}
?>

Explanation:

Specify Email Address:

The $email variable is set to "[email protected]", which represents the email address to validate.

Filter Validation:

The filter_var() function is used with the FILTER_VALIDATE_EMAIL filter to check if the $email variable contains a valid email format.

Conditional Check:

An if statement checks the result of filter_var().
If filter_var() returns true (indicating a valid email), the code inside the if block runs.

Output for Valid Email:

If the email is valid, it prints "<email> = Valid" to indicate that the email format is correct.

Output for Invalid Email:

If the email is not valid, it goes to the else block, printing "<email> = Invalid" to indicate an incorrect format.

End of Script:

The code ends after displaying whether the email is valid or invalid.

Output:

"[email protected]" = Valid

filter_var() function:

Syntax:

mixed filter_var ( mixed $variable [, int $filter = FILTER_DEFAULT [, mixed $options ]] )

filter_var() function filters a variable with a specified filter.

Parameters:

variable: Value to filter.
filter: The ID of the filter to apply.
options: Associative array of options or bitwise disjunction of flags.

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to validate multiple email addresses using both FILTER_VALIDATE_EMAIL and regular expressions.
Write a PHP script to validate an email address and perform a DNS lookup to verify the domain exists.
Write a PHP script to sanitize user-supplied emails and output them in a standardized format.
Write a PHP script to accept an array of emails and return a list of those that fail validation.

PHP Code Editor:

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