Regular expression _ regular expression that can write less than 1000 lines of code

Mastering regular expressions skillfully can greatly improve your development efficiency.

Regular expressions are often used for validation of fields or arbitrary strings, such as the following JavaScript code that validates the base date format:

var reg =/^ (\\d{1,4}) (-|\\/) (\\d{1,2}) \\2 (\\d{1,2}) $/;
var r = Fieldvalue.match (reg);  
if (r==null) alert (' Date format error! ');

Here are 20 regular expressions that are frequently used in front-end development:

1. Verify Password strength
the strength of the password must be a combination of uppercase and lowercase letters and numbers, and cannot use special characters, which are between 8-10 lengths.

Copy Code code as follows:

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

2. Check Chinese
the string can only be Chinese.

Copy Code code as follows:

^[\\u4e00-\\u9fa5]{0,}$

3. A string of numbers, 26 English letters, or underscores

^\\w+$

4. Verify e-mail address
As with the password, the following is a regular check statement of the compliance of the e-mail address.

Copy Code code as follows:

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

5. Verify ID Number
The following is a regular check of the ID number. 15 or 18 bits.

15-bit:

Copy Code code as follows:

^[1-9]\\d{7} ((0\\d) | ( 1[0-2])) (([0|1|2]\\d) |3[0-1]) \\d{3}$

18-bit:

Copy Code code as follows:

^[1-9]\\d{5}[1-9]\\d{3} ((0\\d) | ( 1[0-2])) (([0|1|2]\\d) |3[0-1]) \\d{3} ([0-9]| X) $

6. Date of verification
Date checksum in "YYYY-MM-DD" format has been considered for flat leap years.

Copy Code code as follows:

^(?:(?! 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) $

7. Check Amount
Amount checksum, accurate to 2 decimal places.

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

8. Check the phone number
Below is the domestic 13, 15, 18 cell phone number regular expression.

Copy Code code as follows:

^ (13[0-9]|14[5|7]|15[0|1|2|3|5|6|7|8| 9]|18[0|1|2|3|5|6|7|8| 9]) \\d{8}$

9. To determine the version of IE
IE has not yet been completely replaced, many pages still need to do version compatibility, the following is the version of IE check expression.

Copy Code code as follows:

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

10. Verify IP-V4 Address
IP4 the regular statement.

Copy Code code as follows:

\\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

11. Verify IP-V6 Address
IP6 the regular statement.

Copy Code code as follows:

(([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]))

12. Check the prefix of the URL
Many times in application development it is necessary to distinguish between the request being HTTPS or HTTP, and the following expression can be used to remove the prefix of a URL and then logically judge it.

if (!s.match (/^[a-za-z]+:\\/\\//))
{
 s = ' http://' + s;
} 

13. Extract URL link
The following expression filters the URL in a paragraph of text.

Copy Code code as follows:

^ (F|HT) {1} (TP|TPS): \\/\\/([\\w-]+\\.) +[\\w-]+ ( \\/[\\w-/?%&=]*)?

14. File path and extend the examination of famous schools
Verifying file paths and extensions

Copy Code code as follows:

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

15. Extract Color Hex codes
Sometimes you need to extract the color code from a Web page, and you can use the following expression.

\\# ([a-fa-f]| [0-9]) {3,6}

16. Extract Web Images
If you want to extract all the picture information from a Web page, you can use the following expression.

Copy Code code as follows:

\\< *[IMG][^\\>]*[SRC] *= *[\\ "\"]{0,1} ([^\\ \ \ \ >]*)

17. Extract Page Hyperlink
Extracts the hyperlinks in HTML.

Copy Code code as follows:

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

18. Refine CSS
The following expression allows you to search for CSS of the same attribute value to refine your code.

Copy Code code as follows:

^\\s*[a-za-z\\-]+\\s*[:]{1}\\s[a-za-z0-9\\s.#]+[;] {1}

19. Extract Notes
If you need to remove the annotation in HMTL, you can use the following expression.

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

20. Matching HTML tags
The following expression can be used to match the tags in HTML.

Copy Code code as follows:

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

Can write less 1000 lines of code 20 regular expressions, quickly to learn!