strstr() for learning PHP string function
This article mainly introduces strstr() for learning PHP string function. This article explains its definition, usage and parameters. Description, tips and comments as well as multiple usage examples, friends in need can refer to it
The code is as follows:
/*
Definition and Usage
The strstr() function searches for the first occurrence of one string within another string.
This function returns the rest of the string (from the matching point). Returns false if the searched string is not found.
Grammar
string strstr (string, search)
Parameter Description
string required. Specifies the string to be searched for.
search required. Specifies the string to search for. If the argument is a number, searches for characters matching the numeric ASCII value
Tips and Notes
Note: This function is binary safe.
Note: This function is case sensitive. For case-insensitive searches, use stristr().
If you just want to determine whether the needle exists in the haystack, use the faster and less memory-intensive strpos() function.
*/
$str = ".The specified string to be searched";
$s = "of";
echo strstr($str,$s) . "
";
echo mb_strstr($str,$s, 'utf-8') . "
";
echo mb_strstr($str,$s, true, 'utf-8') . "
";
echo mb_strstr($str,$s, false, 'utf-8') . "
";
/*
Definition and Usage
The strrchr() function finds the last occurrence of a string within another string and returns all characters from that position to the end of the string.
If successful, return false otherwise.
Grammar
strrchr(string,char)
Parameter Description
string required. Specifies the string to be searched for.
char required. Specifies the characters to search for. If the argument is a number, searches for characters matching the numeric ASCII value.
*/
echo strrchr($str,$s) . "
";
echo mb_strrchr($str,$s, 'utf-8') . "
";
echo mb_strrchr($str,$s, true, 'utf-8') . "
";
echo mb_strrchr($str,$s, false, 'utf-8') . "
";
$str = "Hello world!Hello world!";
$s = "world";
echo strrchr($str,$s) . "
";
echo mb_strrchr($str,$s, 'utf-8') . "
";
echo mb_strrchr($str,$s, true, 'utf-8') . "
";
echo mb_strrchr($str,$s, false, 'utf-8') . "
";
/*
Definition and Usage
The strtr() function converts specific characters in a string.
Grammar
strtr(string,from,to)
or
strtr(string,array)
Parameter Description
string1 required. Specifies the string to be converted.
from Required (unless using an array). Specifies the character to be changed.
to Required (unless using an array). Specifies the character to change to.
array Required (unless from and to are used). An array where the keys are the original characters and the values are the target characters.
Description
If from and to are of different lengths, format to the shortest length.
*/
echo strtr("Hilla Warld","ia","eo"). "
";
$arr = array("Hello" => "Hi", "world" => "earth");
echo strtr("Hello world",$arr). "
";
echo strtr("If omitted, use internal character encoding", "internal", "external"). "
";
$arr = array("if" => "if", "then" => "then");
echo strtr("If omitted, internal character encoding is used",$arr). "
";
?>

ThesecrettokeepingaPHP-poweredwebsiterunningsmoothlyunderheavyloadinvolvesseveralkeystrategies:1)ImplementopcodecachingwithOPcachetoreducescriptexecutiontime,2)UsedatabasequerycachingwithRedistolessendatabaseload,3)LeverageCDNslikeCloudflareforservin

You should care about DependencyInjection(DI) because it makes your code clearer and easier to maintain. 1) DI makes it more modular by decoupling classes, 2) improves the convenience of testing and code flexibility, 3) Use DI containers to manage complex dependencies, but pay attention to performance impact and circular dependencies, 4) The best practice is to rely on abstract interfaces to achieve loose coupling.

Yes,optimizingaPHPapplicationispossibleandessential.1)ImplementcachingusingAPCutoreducedatabaseload.2)Optimizedatabaseswithindexing,efficientqueries,andconnectionpooling.3)Enhancecodewithbuilt-infunctions,avoidingglobalvariables,andusingopcodecaching

ThekeystrategiestosignificantlyboostPHPapplicationperformanceare:1)UseopcodecachinglikeOPcachetoreduceexecutiontime,2)Optimizedatabaseinteractionswithpreparedstatementsandproperindexing,3)ConfigurewebserverslikeNginxwithPHP-FPMforbetterperformance,4)

APHPDependencyInjectionContainerisatoolthatmanagesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itactsasacentralhubforcreatingandinjectingdependencies,thusreducingtightcouplingandeasingunittesting.

Select DependencyInjection (DI) for large applications, ServiceLocator is suitable for small projects or prototypes. 1) DI improves the testability and modularity of the code through constructor injection. 2) ServiceLocator obtains services through center registration, which is convenient but may lead to an increase in code coupling.

PHPapplicationscanbeoptimizedforspeedandefficiencyby:1)enablingopcacheinphp.ini,2)usingpreparedstatementswithPDOfordatabasequeries,3)replacingloopswitharray_filterandarray_mapfordataprocessing,4)configuringNginxasareverseproxy,5)implementingcachingwi

PHPemailvalidationinvolvesthreesteps:1)Formatvalidationusingregularexpressionstochecktheemailformat;2)DNSvalidationtoensurethedomainhasavalidMXrecord;3)SMTPvalidation,themostthoroughmethod,whichchecksifthemailboxexistsbyconnectingtotheSMTPserver.Impl


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

Zend Studio 13.0.1
Powerful PHP integrated development environment

Atom editor mac version download
The most popular open source editor

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 Mac version
God-level code editing software (SublimeText3)
