Regular Expressions and Regular Expressions

Regular Expressions and Regular Expressions
1. ^ \ D + $ // Note: match a non-negative integer (positive integer + 0)
2. ^ [0-9] * [1-9] [0-9] * $ // Note: match a positive integer
3. ^ (-\ D +) | (0 +) $ // Note: match a non-positive integer (negative integer + 0)
4. ^-[0-9] * [1-9] [0-9] * $ // Note: match a negative integer
5. ^ -? \ D + $ // annotation: matches an integer positive integer and pays an integer and 0
6. ^ \ D + (\. \ d + )? $ // Annotation: Match non-negative floating point number (Positive floating point number + 0)
7. ^ ([0-9] + \. [0-9] * [1-9] [0-9] *) | ([0-9] * [1-9] [0-9] * \. [0-9] +) | ([0-9] * [1-9] [0-9] *) $ // Note: match the Positive floating point number
8. ^ (-\ D + (\. \ d + )?) | (0 + (\. 0 + )?)) $ // Annotation: match a non-Positive floating point number (negative floating point number + 0)
9. ^ (-([0-9] + \. [0-9] * [1-9] [0-9] *) | ([0-9] * [1-9] [0-9] * \. [0-9] +) | ([0-9] * [1-9] [0-9] *) $ // annotation: matches a negative floating point number.
10. ^ (-? \ D +) (\. \ d + )? $ // Annotation: Match floating point number
11. ^ [A-Za-z] + $ // Note: match A string consisting of 26 English letters
12. ^ [A-Z] + $ // Note: match a string consisting of 26 uppercase letters
13. ^ [A-z] + $ // Note: match a string consisting of 26 lower-case letters
14. ^ [A-Za-z0-9] + $ // Note: match a string consisting of digits and 26 letters
15. ^ \ W + $ // Note: match a string consisting of digits, 26 English letters, or underscores
16. ^ [\ W-] + (\. [\ w-] +) * @ [\ w-] + (\. [\ w-] +) + $ // Note: matching email address
17. ^ [A-zA-z] +: // Note: match (\ w + (-\ w + )*)(\. (\ w + (-\ w + )*))*(\? \ S *)? $ // Annotation: matching url
18. Note: Regular Expression matching Chinese characters: [\ u4e00-\ u9fa5]
19. Note: Match double-byte characters (including Chinese characters): [^ \ x00-\ xff]
20. Application: Calculate the length of a string (two-byte length Meter 2, ASCII character meter 1)
String. prototype. len = function () {return this. replace ([^ \ x00-\ xff]/g, "aa"). length ;}
21. Note: Regular Expression matching empty rows: \ n [\ s |] * \ r
22. Note: Regular Expressions matching HTML tags:/<(. *)>. * <\/\ 1> | <(. *) \/>/
23. Note: Regular Expressions matching spaces at the beginning and end are as follows: (^ \ s *) | (\ s * $)


* Use Cases of Regular Expressions
* 1, ^ \ S + [a-z A-Z] $ cannot be blank cannot have spaces can only be English letters
* 2. \ S {6,} cannot be empty for more than six characters
* 3. ^ \ d + $ cannot contain spaces or non-numbers.
* 4. (. *) (\. jpg | \. bmp) $ can only be in jpg and bmp formats.
* 5. ^ \ d {4} \-\ d {} $ can only be in the format of 2004-10-22
* 6. select at least one item for ^ 0 $.
* 7. ^ 0 {2,} $ select at least two items.
* 8. ^ [\ s | \ S] {20,} $ cannot be empty for more than 20 words
* 9. ^ \ +? [A-z0-9] ([-+.] | [_] + )? [A-z0-9] +) * @ ([a-z0-9] + (\. | \-) + [a-z] {2, 6} $ email
* 10. \ w + ([-+.] \ w +) * @ \ w + ([-.] \ w + )*\. \ w + ([-.] \ w +) * ([,;] \ s * \ w + ([-+.] \ w +) * @ \ w + ([-.] \ w + )*\. \ w + ([-.] \ w +) * enter multiple addresses separated by commas (,) or spaces.
* 11, ^ (\ ([0-9] + \))? [0-9] {87341628} $ a telephone number with a 7-or 8-digit phone number or a District Code such as (022)
* 12, ^ [a-z A-Z 0-9 _] + @ [a-z A-Z 0-9 _] + (\. [a-z A-Z 0-9 _] +) + (\, [a-z A-Z 0-9 _] + @ [a-z A-Z 0-9 _] + (\. [a-z A-Z 0-9 _] +) * $
* Only letters, numbers, and underscores are allowed. @ and. must be in the same format as a standard email.
* 13 ^ \ w + @ \ w + (\. \ w +) + (\, \ w + @ \ w + (\. \ w +) * $ the above expression can also be written in this way, which is more refined.
14 ^ \ w + (-\ w +) | (\. \ w +) * \ @ \ w + ((\. |-) \ w + )*\. \ w + $ [/size]