1Symfony Polyfill / Php73 2======================== 3 4This component provides functions added to PHP 7.3 core: 5 6- [`array_key_first`](https://php.net/array_key_first) 7- [`array_key_last`](https://php.net/array_key_last) 8- [`hrtime`](https://php.net/function.hrtime) 9- [`is_countable`](https://php.net/is_countable) 10- [`JsonException`](https://php.net/JsonException) 11 12More information can be found in the 13[main Polyfill README](https://github.com/symfony/polyfill/blob/main/README.md). 14 15License 16======= 17 18This library is released under the [MIT license](LICENSE). 19