Summary of commonly used regular expressions in php_PHP tutorial

This article collects a summary of some commonly used regular expression rules in PHP. Friends in need can refer to it.

Match specific numbers:

The code is as follows

Copy code

代码如下	复制代码
^[1-9]d*$　 　 //匹配正整数 ^-[1-9]d*$ 　 //匹配负整数 ^-?[1-9]d*$　　 //匹配整数 ^[1-9]d*|0$　 //匹配非负整数（正整数 + 0） ^-[1-9]d*|0$　　 //匹配非正整数（负整数 + 0） ^[1-9]d*.d*|0.d*[1-9]d*$　　 //匹配正浮点数 ^-([1-9]d*.d*|0.d*[1-9]d*)$　 //匹配负浮点数 ^-?([1-9]d*.d*|0.d*[1-9]d*|0?.0+|0)$　 //匹配浮点数 ^[1-9]d*.d*|0.d*[1-9]d*|0?.0+|0$　　 //匹配非负浮点数（正浮点数 + 0） ^(-([1-9]d*.d*|0.d*[1-9]d*))|0?.0+|0$　　//匹配非正浮点数（负浮点数 + 0）

^[1-9]d*$　 ​​// Match positive integers

^-[1-9]d*$ //Match negative integers

^-?[1-9]d*$　 ​​//Match integers

^[1-9]d*|0$ // Match non-negative integers (positive integers + 0)

^-[1-9]d*|0$　 // Match non-positive integers (negative integers + 0)

代码如下	复制代码
^[A-Za-z]+$　　//匹配由26个英文字母组成的字符串 ^[A-Z]+$　　//匹配由26个英文字母的大写组成的字符串 ^[a-z]+$　　//匹配由26个英文字母的小写组成的字符串 ^[A-Za-z0-9]+$　　//匹配由数字和26个英文字母组成的字符串 ^w+$　　//匹配由数字、26个英文字母或者下划线组成的字符串 评注：最基本也是最常用的一些表达式

^[1-9]d*.d*|0.d*[1-9]d*$　 ​​//Match positive floating point numbers

^-([1-9]d*.d*|0.d*[1-9]d*)$ //Match negative floating point numbers
^-?([1-9]d*.d*|0.d*[1-9]d*|0?.0+|0)$ //Match floating point number

^[1-9]d*.d*|0.d*[1-9]d*|0?.0+|0$　 // Match non-negative floating point numbers (positive floating point numbers + 0)

^(-([1-9]d*.d*|0.d*[1-9]d*))|0?.0+|0$　 //Match non-positive floating point numbers (negative floating point numbers + 0 )

代码如下	复制代码
$str = "php编程"; if (preg_match("/^[x{4e00}-x{9fa5}]+$/u",$str)) { print("该字符串全部是中文"); } else { print("该字符串不全部是中文"); }

Comment: Useful when processing large amounts of data, please pay attention to corrections in specific applications

Match specific string:

The code is as follows

Copy code

^[A-Za-z]+$　 // Matches a string consisting of 26 English letters

^[A-Z]+$　 // Matches a string consisting of 26 uppercase English letters

^[a-z]+$　 // Matches a string consisting of 26 lowercase English letters

^[A-Za-z0-9]+$　 // Matches a string consisting of numbers and 26 English letters

代码如下

复制代码

$str = "singlepoint单点日志"; if (preg_match("/^[x{4e00}-x{9fa5}]+$/u",$str)) { print("该字符串全部是中文"); } else { print("该字符串不全部是中文"); } $alias_len = mb_strlen($value['alias'], "utf-8"); $temp_array = array(); for($i = 0;$i {  $temp_array[$i] = mb_substr($value['alias'],$i,1,"utf-8");  if(ord(substr($temp_array[$i],0,1))>'0xe0' && strlen($temp_array[$i])      $temp_array[$i] = ''; } $value['alias'] = implode('',$temp_array);

^w+$　 // Matches a string consisting of numbers, 26 English letters or underscores Comment: Some of the most basic and commonly used expressions

Regular expression to match Chinese characters: [u4e00-u9fa5] Example

The code is as follows	Copy code
$str = "php programming"; if (preg_match("/^[x{4e00}-x{9fa5}]+$/u",$str)) { print("This string is all in Chinese"); } else { print("This string is not all Chinese"); }

Comment: Matching Chinese characters is really a headache, but with this expression it’s easier to do Match double-byte characters (including Chinese characters): [^x00-xff] Example

The code is as follows

Copy code

$str = "singlepoint log"; if (preg_match("/^[x{4e00}-x{9fa5}]+$/u",$str)) { print("This string is all in Chinese"); } else { print("This string is not all Chinese"); } $alias_len = mb_strlen($value['alias'], "utf-8"); $temp_array = array(); for($i = 0;$i { $temp_array[$i] = mb_substr($value['alias'],$i,1,"utf-8"); if(ord(substr($temp_array[$i],0,1))>'0xe0' && strlen($temp_array[$i]) $temp_array[$i] = ''; } $value['alias'] = implode('',$temp_array);

Comment: Coding table double-byte character encoding range 1. GBK (GB2312/GB18030) x00-xff GBK double-byte encoding range x20-x7f ASCII

xa1-xff Chinese gb2312 x80-xff Chinese gbk 2. UTF-8 (Unicode) u4e00-u9fa5 (Chinese) x3130-x318F (Korean

xAC00-xD7A3 (Korean) u0800-u4e00 (Japanese)

Regular expression matching blank lines: ns*r

| Select matching, similar to the usage of || in php ^ Match the content at the beginning of the string

The code is as follows

代码如下	复制代码
$str = "123 456"; $patten = "/s+/"; $result = split($patten,$str); echo join(" ",$result);

Copy code

$str = "123 456";
$patten = "/s+/";

$result = split($patten,$str);

echo join("
",$result);

Comment: Can be used to delete blank lines

Regular expression matching HTML tags: ]*>.*?1>|<.>

Comment: The version circulating on the Internet is too bad. The above one can only match part of it, and it is still powerless for complex nested tags

Regular expression matching leading and trailing whitespace characters: ^s*|s*$

Comment: It can be used to delete whitespace characters (including spaces, tabs, form feeds, etc.) at the beginning and end of the line. A very useful expression

Regular expression matching email addresses: w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*

Comment: Very useful for form validation

Regular expression matching URL: [a-zA-z]+://[^s]*

Comment: The version circulating on the Internet has very limited functions. The above one can basically meet the needs

Is the matching account legal (starting with a letter, 5-16 bytes allowed, alphanumeric underscores allowed): ^[a-zA-Z][a-zA-Z0-9_]{4,15}$

Comment: Very useful for form validation

Match domestic phone numbers: d{3}-d{8}|d{4}-d{7}

Comment: Matching format such as 0511-4405222 or 021-87888822

Matches Tencent QQ number: [1-9][0-9]{4,}

Comment: Tencent QQ account starts from 10000

Match Chinese postal code: [1-9]d{5}(?!d)

Comment: China’s postal code is a 6-digit number

Matching ID card: d{15}|d{18}
Comment: China’s ID card has 15 or 18 digits

Matching ip address: d+.d+.d+.d+
Comment: Useful when extracting IP address

Contents related to regular expressions that may be useful to you

One, a-z A-Z_0-9 //The most common characters

2. (bfw)(sda) //Unit symbol enclosed in parentheses, one parentheses represents a whole

3. [sdwe][^mjnb] //Atom table enclosed in square brackets. ^ in the atom table represents exclusion or opposite content
4. Escape character
d contains all numbers [0-9]
D except all numbers [^0-9]
w contains all English characters [a-zA-Z_0-9]
W except all English characters [^a-zA-Z_0-9] -----match special characters
s contains blank areas such as carriage return, line feed, page break, etc.[fnr]

4, regular expression metacharacter

* Matches the previous content 0 or more times
. Match the content 0 or more times, but do not include carriage returns and line feeds
+ Match the previous content 1 or more times

? Matches 0 or 1 times of the previous content

$ matches the content at the end of the string b matches word boundaries, which can be spaces or special symbols

B matches except unexpected content with word boundaries

{m} matches the previous content repeated m times {m,} matches the number of repetitions of the previous content greater than or equal to m times {m,n} matches the number of repetitions of the previous content from m to n times () Merge the overall match and put it into memory. You can use 12 to get the call in sequence http://www.bkjia.com/PHPjc/633088.html

www.bkjia.comtrue

http: //www.bkjia.com/PHPjc/633088.htmlTechArticleThis article collects a summary of some commonly used regular expression rules in php. Friends in need can refer to it. . Match specific numbers: The code is as follows Copy code ^[1-9]d*$ //Match positive integers...