Editing Regular expression in Mandarin (section)

== Troubleshooting of regular expression ==
Tips
* Use online tool [https://regex101.com/ regex101: build, test, and debug regex] to obtain the explain of your syntax
* Small data test: (1) Prepare the small file data to verify the syntax (2) Using the [[Regular_expression#Regular_expression_online_tools | online tools]]
* Highlight or output the matched text e.g. {{kbd | key=<nowiki>--color</nowiki>}}<ref>[https://www.cyberciti.biz/faq/howto-use-grep-command-in-linux-unix/grep_command_examples/ Grep -color command Examples - nixCraft]</ref> for grep command or output the matches by PHP [http://php.net/manual/en/function.preg-match.php preg_match()] function.
* Simplify the syntax
* Because the compatibility issue, you may try to use the alternative syntax e.g. {{kbd | key=<nowiki>\d</nowiki>}} to {{kbd | key=<nowiki>[0-9]+</nowiki>}}.

Related articles
* [https://errerrors.blogspot.com/2015/07/sublime-text-invalid-lookbehind.html Err: 解決 Sublime Text 正則表示式搜尋，遇到的「Invalid lookbehind assertion」錯誤]