PHP to validate and sanitize phone numbers

PHP Code Solution for Validating and Sanitizing Phone Numbers

<?php

// Regular expression for validating phone numbers
$phoneRegex = '/^(?:\+?(\d{1,2}))?[-. (]*(\d{3})[-. )]*(\d{3})[-. ]*(\d{4})$/';

// Function to validate a phone number
function validatePhoneNumber($phoneNumber) {
    global $phoneRegex;
    return preg_match($phoneRegex, $phoneNumber);
}

// Function to sanitize a phone number
function sanitizePhoneNumber($phoneNumber) {
    global $phoneRegex;
    return preg_replace('/[^0-9]/', '', $phoneNumber);
}

// Test the functions
$phoneNumber = '123-456-7890';

if (validatePhoneNumber($phoneNumber)) {
    echo "Valid phone number: $phoneNumber<br>";
} else {
    echo "Invalid phone number: $phoneNumber<br>";
}

$sanitizedPhoneNumber = sanitizePhoneNumber($phoneNumber);
echo "Sanitized phone number: $sanitizedPhoneNumber<br>";
?>

How it Works

The code above uses regular expressions to validate and sanitize phone numbers.

Validation

The validatePhoneNumber() function uses the preg_match() function to check if the input string matches the $phoneRegex regular expression. If the input string matches the regular expression, the function returns true, indicating that the phone number is valid. Otherwise, the function returns false.

Sanitization

The sanitizePhoneNumber() function uses the preg_replace() function to remove all non-digit characters from the input string. This results in a sanitized phone number that contains only digits.

How to Implement It Effectively

To implement this code effectively, you should:

1. Define a clear and consistent naming convention for your functions and variables.
2. Use descriptive comments to explain what your code does.
3. Test your code thoroughly to ensure that it works correctly.
4. Use a library or framework that provides phone number validation and sanitization functionality. This will save you time and effort, and it will help you to avoid potential security vulnerabilities.