Common Regular Expression Collections _ regular expressions

In computer science, regular expressions are used to describe or match a sequence of strings that conform to a certain syntactic rule. In web development, regular expressions are often used to detect, find, and replace certain strings that conform to rules, such as detecting the correctness of user input E-mai formats, gathering page content that matches the rules, and so on.

Today I will use PHP and JavaScript to introduce you to the most commonly used in web development and the most useful regular expressions and their usage, regular expression is a subject, it is impossible to use an article to explain the end of the theory of things online a lot of interested students can search a bunch of. But you may not need to bury yourself in the study of the elusive regular expression, look at this article and the examples to show you the common, practical regular expression.

PHP Common expression Usage

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

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

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

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

5. Matching URL: ((f|ht) {1} (TP|TPS)://) [-a-za-z0-9@:%_\+.~#?&//=]+)

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

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

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

9. Matching 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. Matching Chinese mainland ID 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"; 
$preg = "/^[\x{4e00}-\x{9fa5}]+$/u"; Match Chinese 
if (Preg_match ($preg, $str, $arr)) { 
   $msg = ' Match succeeded! '; 
} else{ 
   $msg = ' match failed! '; 
} 

javascript Common expression usage

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

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

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

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

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

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

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

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

9. Matching 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. Matching Chinese mainland ID 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) $/

JavaScript Regular Validation String Method Example:

var str = "abc@126.com"; 
var preg =/^\w+ ([-+.] \w+) *@\w+ ([-.] \w+) *\.\w+ ([-.] \w+) * * *; Match email 
if (preg.test (str)) { 
  var msg = "Match succeeded"; 
} else{ 
  var msg = "Match failed!" "; 
} 
Alert (msg);

Well, today's regular expression is about this, I hope you enjoy my tutorials and get help from it. Let's go over the next instance.