Edit requests of PHP:文字列が整数かの検証にはis_numeric, ctype_digit, filter_varどれが適切か？

Please check the preview of this article

We released Markdown parser changes on February 24, 2022. There may be some unexpected appearance changes in this update, because this article was posted before the changes.
Please don't forget to check the preview before updating your article.
For more information on the changes, please read this article.