How can language files be efficiently integrated into PHP websites for multilingual support?

To efficiently integrate language files into PHP websites for multilingual support, you can use PHP arrays to store key-value pairs of language strings. By including a language file based on the user's preferred language, you can easily access and display the appropriate language strings throughout your website.

// Function to load language file based on user's preferred language
function loadLanguageFile($lang) {
    $languageFile = 'languages/' . $lang . '.php';
    if (file_exists($languageFile)) {
        return include($languageFile);
    } else {
        return [];
    }
}

// Include the appropriate language file based on user's preferred language
$preferredLanguage = 'en'; // Example: English language
$language = loadLanguageFile($preferredLanguage);

// Access language strings using array keys
echo $language['welcome_message'];