


[PHP] A simple and wonderful way to get the length of Chinese string_PHP tutorial
When I was writing the form validation class of the framework tonight, I needed to determine whether the length of a certain string was within a specified range. Naturally, I thought of the strlen function in PHP.
$str = 'Hello world!';
echo strlen($str); // Output 12
However, among the functions that come with PHP, strlen and mb_strlen both calculate the length by calculating the number of bytes occupied by the string. Under different encoding conditions, the number of bytes occupied by Chinese is different. Under GBK/GB2312, Chinese characters occupy 2 bytes, while under UTF-8, Chinese characters occupy 3 bytes.
$str = 'Hello world! ';
echo strlen($str); // Output 12 under GBK or GB2312, output 18 under UTF-8
When we judge the length of a string, we often need to judge the number of characters, not the number of bytes occupied by the string. For example, this PHP code under UTF-8:
$name = 'Zhang Gengchang';
$len = strlen($name);
// Output FALSE, because three Chinese characters occupy 9 bytes under UTF-8
if($len >= 3 && $len
echo 'TRUE';
}else{
echo 'FALSE';
}
So is there any convenient and practical way to get the length of a Chinese string? You can use regular rules to calculate the number of Chinese characters, divide by 2 under GBK/GB2312 encoding, divide by 3 under UTF-8 encoding, and finally add the length of the non-Chinese string, but this is too troublesome, WordPress There is a more beautiful piece of code in , refer to it as follows:
$str = 'Hello, world! ';
preg_match_all('/./us', $str, $match);
echo count($match[0]); // Output 9
The idea is to use regular expressions to split the string into single characters, and directly use count to calculate the number of matching characters, which is the result we want.

TomakePHPapplicationsfaster,followthesesteps:1)UseOpcodeCachinglikeOPcachetostoreprecompiledscriptbytecode.2)MinimizeDatabaseQueriesbyusingquerycachingandefficientindexing.3)LeveragePHP7 Featuresforbettercodeefficiency.4)ImplementCachingStrategiessuc

ToimprovePHPapplicationspeed,followthesesteps:1)EnableopcodecachingwithAPCutoreducescriptexecutiontime.2)ImplementdatabasequerycachingusingPDOtominimizedatabasehits.3)UseHTTP/2tomultiplexrequestsandreduceconnectionoverhead.4)Limitsessionusagebyclosin

Dependency injection (DI) significantly improves the testability of PHP code by explicitly transitive dependencies. 1) DI decoupling classes and specific implementations make testing and maintenance more flexible. 2) Among the three types, the constructor injects explicit expression dependencies to keep the state consistent. 3) Use DI containers to manage complex dependencies to improve code quality and development efficiency.

DatabasequeryoptimizationinPHPinvolvesseveralstrategiestoenhanceperformance.1)Selectonlynecessarycolumnstoreducedatatransfer.2)Useindexingtospeedupdataretrieval.3)Implementquerycachingtostoreresultsoffrequentqueries.4)Utilizepreparedstatementsforeffi

PHPisusedforsendingemailsduetoitsbuilt-inmail()functionandsupportivelibrarieslikePHPMailerandSwiftMailer.1)Usethemail()functionforbasicemails,butithaslimitations.2)EmployPHPMailerforadvancedfeatureslikeHTMLemailsandattachments.3)Improvedeliverability

PHP performance bottlenecks can be solved through the following steps: 1) Use Xdebug or Blackfire for performance analysis to find out the problem; 2) Optimize database queries and use caches, such as APCu; 3) Use efficient functions such as array_filter to optimize array operations; 4) Configure OPcache for bytecode cache; 5) Optimize the front-end, such as reducing HTTP requests and optimizing pictures; 6) Continuously monitor and optimize performance. Through these methods, the performance of PHP applications can be significantly improved.

DependencyInjection(DI)inPHPisadesignpatternthatmanagesandreducesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itallowspassingdependencieslikedatabaseconnectionstoclassesasparameters,facilitatingeasiertestingandscalability.

CachingimprovesPHPperformancebystoringresultsofcomputationsorqueriesforquickretrieval,reducingserverloadandenhancingresponsetimes.Effectivestrategiesinclude:1)Opcodecaching,whichstorescompiledPHPscriptsinmemorytoskipcompilation;2)DatacachingusingMemc


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Dreamweaver Mac version
Visual web development tools

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

SublimeText3 English version
Recommended: Win version, supports code prompts!

WebStorm Mac version
Useful JavaScript development tools
