Effect Regular Expression Example

Regular expressions can be used to quickly match a very complex text logic using only a very short expression statement. Mastering regular expressions skillfully can greatly improve your development efficiency. This article will show you some regular expressions which are commonly used.

1. Effect Regular Expression Example.

1. A string of numbers, English letters, or underscores.

   ^\\w+$

2. Check date. The below regular expression has considered date validation of the “yyyy-mm-dd” format for leap years.

   ^(?:(?!0000)[0-9]{4}-(?:(?:0[1-9]|1[0-2])-(?:0[1-9]|1[0-9]|2[0-8])|(?:0[13-9]|1[0-2])-(?:29|30)|(?:0[13578]|1[02])-31)|(?:[0-9]{2}(?:0[48]|[2468][048]|[13579][26])|(?:0[48]|[2468][048]|[13579][26])00)-02-29)$

3. Verify password strength. In the below regular expression, the password length is between 8 and 10, the strength must be a combination of upper and lower case letters and numbers, no special characters.

   ^(?=.*\\d)(?=.*[a-z])(?=.*[A-Z]).{8,10}$

4. Verify e-mail address.

   [\\w!#$%&'*+/=?^_`{|}~-]+(?:\\.[\\w!#$%&'*+/=?^_`{|}~-]+)*@(?:[\\w](?:[\\w-]*[\\w])?\\.)+[\\w](?:[\\w-]*[\\w])?

5. Check IE version.

   ^.*MSIE [5-8](?:\\.[0-9]+)?(?!.*Trident\\/[5-9]\\.0).*$

6. Check amount, accurate to 2 decimal digit.

   ^[0-9]+(.[0-9]{2})?$

7. Match HTML tags. The following expression can match the HTML tag attributes.

   <\\/?\\w+((\\s+\\w+(\\s*=\\s*(?:".*?"|'.*?'|[\\^'">\\s]+))?)+\\s*|\\s*)\\/?>

8. Match CSS properties. The following expression allows you to search for matching CSS properties.

   ^\\s*[a-zA-Z\\-]+\\s*[:]{1}\\s[a-zA-Z0-9\\s.#]+[;]{1}

9. Match HTML comments. If you need to match HTML comments, use the following expression.

   <!--(.*?)-->

10. Match Html hyperlink.

    (<a\\s*(?!.*\\brel=)[^>]*)(href="https?:\\/\\/)((?!(?:(?:www\\.)?'.implode('|(?:www\\.)?', $follow_list).'))[^"]+)"((?!.*\\brel=)[^>]*)(?:[^>]*)>

11. Match web images.

    \\< *[img][^\\\\>]*[src] *= *[\\"\\']{0,1}([^\\"\\'\\ >]*)

12. Match color hex codes.

    ^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$

13. Match URL link.

    ^(f|ht){1}(tp|tps):\\/\\/([\\w-]+\\.)+[\\w-]+(\\/[\\w- ./?%&=]*)?

14. Verify file path and extension for windows. The below example will match the file extension that is .txt.

    ^([a-zA-Z]\\:|\\\\)\\\\([^\\\\]+\\\\)*[^\\/:*?"<>|]+\\.txt(l)?$

15. Check IP-V6 IP address.

    (([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))

16. Check IP-V4 IP address.

    \\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\b