Regular expressions improve the efficiency of the Code __ regular expressions

This post finally by the end of the Tianya prawns in 2017-3-23 14:30 edit Regular expressions, a very old and powerful text-processing tool, can quickly implement a very complex business logic with a very short expression statement. 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}) $/; var r = Fieldvalue.match (reg); if (r==null) alert (' Date format error! '); Copy code The following are the 20 regular expressions that are often used in the front-end development to be collated by the craftsman. 1. Verify password strength The strength of the password must be a combination of uppercase and lowercase letters and numbers, and cannot use special characters, which are between 8-10 lengths. ^ (? =.*\\d) (? =.*[a-z]) (? =.*[a-z]). {8,10}$ Copy Code 2. Verify that Chinese strings can only be Chinese. ^[\\u4e00-\\u9fa5]{0,}$ Copy Code 3. A string of numbers, 26 English letters, or underscores ^\\w+$ Copy Code 4. Check the e-mail address with the same password, the following is the e-mail address compliance regular Check statement. [\\w!#$%& ' *+/=?^_ ' {|} ~-]+(?:\ \. [\\w!#$%& ' *+/=?^_ ' {|} ~-]+) *@ (?: [\\w] (?: [\\w-]*[\\w]) +[\\w] (?: [\\w-]*[\\w])? Copy Code 5. Verify the ID number under the ID card number of the regular check. 15 or 18 bits. 15-bit: ^[1-9]\\d{7} ((0\\d) | ( 1[0-2])) (([0|1|2]\\d) |3[0-1]) \\d{3}$ copy code 18 bits: ^[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) $ copy Code 6. Check date "YYYY-MM-DD" format date check, has been considered the flat leap year. ^(?:(?! 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) $ copy Code 7. Check the amount of verification, accurate to 2 decimal places. ^[0-9]+ (. [ 0-9]{2})? $ copy Code 8. Check the phone number below is the domestic 13, 15, 18, the beginning of the mobile phone number regular expression. (Can be expanded according to the current domestic collection number of the first two-digit opening number) ^ (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}$ Copy Code 9. To determine IE version of IE has not been completely replaced, many pages still need to do version compatibility, the following is the version of the Internet Explorer expression. ^.*msie [5-8] (?: \ \. [0-9]+]? (?!. *trident\\/[5-9]\\.0). *$ Copy Code 10. Verify the IP-V4 address IP4 regular statement. \\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 Copy Code 11. Verify the IP-V6 address IP6 regular statement. (([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]) copy code 12. Check URL prefix application development many times the need to distinguish between the request is HTTPS or HTTP, through the following expression can take out a URL prefix and then logically judge. if (!s.match (/^[a-za-z]+:\\/\\//)) {s = ' http://' + s;} Copy Code 13. Extract URL link below This expression can filter out a paragraph of text in the URL. ^ (F|HT) {1} (TP|TPS): \\/\\/([\\w-]+\\.) +[\\w-]+ (\\/[\\w-/?%&=]*)? Copy Code 14. File path and extended prestigious school verification verify the file path and extension under Windows (. txt file in the following example) ^ ([a-za-z]\\:|\\\\) \\\\ ([^\\\\]+\\\\) *[^\\/:*? " <>|] +\\.txt (l)? $ copy Code 15. Extract color Hex codes Sometimes you need to extract the colour code from a Web page, you can use the following expression. ^# ([a-fa-f0-9]{6}| [A-fa-f0-9] {3}) $ copy Code 16. Extract the image of the Web page if you want to extract all the image information on the page, you can use the following expression. \\< *[IMG][^\\\\&GT;]*[SRC] *= *[\\ "\"]{0,1} ([^\\ "\ \ \ >]*) Copy code 17. Extract the hyperlinks in the HTML from the page hyperlinks. (<a\\s* (?!. *\\brel=) [^>]*) (href= "https?:\ \/\\/)((?! (:(?: www\\.)? '. Implode (' |: www\\.)? ', $follow _list) [^"]+)"((?!. *\\brel=) [^>]*] (?: [^>]*) > Copy Code 18. Find CSS properties by using the following expression, you can search for a matching CSS property. ^\\s*[a-za-z\\-]+\\s*[:]{1}\\s[a-za-z0-9\\s.#]+[;] {1} Copying code 19. Extract Note If you need to remove the annotation in the HMTL, you can use the following expression. <!--(. *?) --> Copy Code 20. Matching HTML tags you can match the label properties in HTML with the following expression. <\\/?\\w+ ((\\s+\\w+) (\\s*=\\s* (?:). *? "| '. *?'| [\\^ ' ">\\s]+)") +\\s*|\\s*) \\/?> Copy Code Original link: http://www.jianshu.com/p/e7bb97218946