Polyfill Php73 Laravel Package

Getting Started

This package provides backward compatibility for PHP 7.3+ features (e.g., array_key_first(), array_key_last(), json_last_error_msg()) when running on older PHP versions (5.3+). To use it:

• Install via Composer: composer require symfony/polyfill-php73
• No manual bootstrap needed—Composer’s autoloader automatically loads polyfills when their functions/classes are missing.
• First use case: write modern PHP 7.3+ code in your app (e.g., $firstKey = array_key_first($array);), and this polyfill ensures it works even on PHP 7.2.

Implementation Patterns

• Transparent usage: Call PHP 7.3+ functions directly in your code; the polyfill detects availability and only defines them if not natively present.
• Composer integration: No configuration required—Composer registers the polyfill via autoload_files.php (via symfony/polyfill’s root composer.json).
• Framework compatibility: Works out-of-the-box with Laravel, Symfony, and other frameworks that rely on Composer autoloading.
• Avoid duplication: If you define a polyfill manually elsewhere (e.g., in a custom bootstrap), ensure it doesn’t conflict—this package’s functions are conditionally defined only when missing.

Gotchas and Tips

• No runtime impact on PHP 7.3+: Functions are only defined when missing, so there’s zero performance overhead on modern PHP versions.
• No backward compat shims: This polyfill only backports core language functions—it doesn’t provide full backward compatibility (e.g., won’t backport abstract trait methods or type hints).
• Never need require/include: Rely solely on Composer’s autoloader; manually including files can cause redeclaration errors.
• Debug tip: Check if a polyfill is active by calling function_exists('array_key_first') before using it (though unnecessary in most cases).
• Extension point: If you use a custom autoloader (e.g., non-Composer setup), manually include vendor/symfony/polyfill-php73/bootstrap.php (but avoid this unless absolutely necessary).