Regular expressions commonly used in web development

In computer science, a regular expression is used to describe or match a series of strings that conform to a certain syntactic rule. In web development, regular expressions are often used to detect and find replacements for certain strings that conform to rules, such as detecting the correctness of user input E-mai format, collecting page content that conforms to rules, and so on.

Today we use PHP and javscript to introduce to you the most commonly used in web development of the most useful regular expressions and their usage, the regular expression is a discipline, it is impossible to use an article to explain, the theory of things online a lot, interested students can search a bunch. But you probably don't have to. Learn elusive regular expressions, see this article and examples to show you a common, useful regular expressions.

PHP Common Expressions Usage

1. Matching positive integers:/^[1-9]\d*$/

2. Match non-negative integers (positive integer +0):/^\d+$/

3. Match Chinese:/^[\x{4e00}-\x{9fa5}]+$/u

4. Match email:/^\w+ ([-+.] \w+) *@\w+ ([-.] \w+) *\.\w+ ([-.] \w+) */

5. Matching URL URL: (((F|HT) {1} (TP|TPS)://) [[Email protected]:%_\+.~#?&//=]+]

6. Match letter start, 5-16 characters, alphanumeric underline:/^[a-za-z][a-za-z0-9_]{4,15}$/

7. Match numbers, letters, underscores, Chinese:/^[\x{4e00}-\x{9fa5}a-za-z0-9_]+$/u

8. Matching China postcode:/^[1-9]\d{5}$/

9. Match 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/

10. Match the Chinese mainland identity card:/^[1-9]\d{5}[1-9]\d{3} ((0\d) | ( 1[0-2]) (([0|1|2]\d) |3[0-1]) \d{3} (\d|x| X) $/

Examples of PHP Regular validation string methods:

$str = "Chinese ah"$preg//if(preg_match($preg, $str,$arr)) {      $msg = ' Match succeeded! ';} Else {      $msg = ' match failed! 'echo$msg;

JavaScript Common expression Usage

1. Matching positive integers:/^[0-9]*[1-9][0-9]*$/

2. Match non-negative integers (positive integer +0):/^\d+$/

3. Match Chinese:/^[\u4e00-\u9fa5]/

4. Match email:/^\w+ ([-+.] \w+) *@\w+ ([-.] \w+) *\.\w+ ([-.] \w+) */

5. Match URL url:/^ (f|ht) {1} (TP|TPS): \/\/([\w-]+\.) +[\w-]+ (\/[\w-./?%&=]*)?

6. Match letter start, 5-16 characters, alphanumeric underline:/^[a-za-z][a-za-z0-9_]{4,15}$/

7. Match numbers, letters, underscores, Chinese:/^[\u4e00-\u9fa5a-za-z0-9_]+$/

8. Matching China postcode:/^[1-9]\d{5}$/

9. Match 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/

10. Match the Chinese mainland identity card:/^[1-9]\d{5}[1-9]\d{3} ((0\d) | ( 1[0-2]) (([0|1|2]\d) |3[0-1]) \d{3} (\d|x| X) $/

Examples of JavaScript Regular validation string methods:

1 varstr = "[Email protected]"; 2 varPreg =/^\w+ ([-+.] \w+) *@\w+ ([-.] \w+) *\.\w+ ([-.] \w+) */;//Match Email3 if(Preg.Test (str)) { 4     varmsg = "Match succeeded"; 5}Else{ 6     varmsg = "Match failed! "; 7 } 8Alert (msg);

Regular expressions commonly used in web development