search
HomeBackend DevelopmentPHP Tutorial每日一博 | PHP中二维数组去除重复项小记

PHP中提供了array_unique函数去除一维数组中的重复项,但是我们实际的项目开发中,从数据库select查询出来的数组经常是二维的;

这里面可能有重复项,这就需要我们自己定义函数进行去除重复项。

思路:

1、首先获取第二维数组的键名,保存在一个数组里面(假设命名为keyname_Arr);

2、然后使用一个符号做分隔符(比如‘-’),将二维数组里面的键值 拼接 成一个字符串,生成一个临时数组;

3、然后使用【array_unique()函数】比较生成的这个临时数组,去掉里面的相同字符串;

4、然后将去除重复后的数组重新组装成二维数组:

在foreach()里面循环使用【explode()函数】,按‘-’分隔符拆分字符串;

同时在foreach()里面对拆分出来的字符串所形成的【新的临时数组tempnew】,再使用一个foreach( $ tempnew as $tempk =>$tempv ),

循环赋值 $output[ $k ][ $ keyname_Arr[ $tempk ]   ] =  tempv ;

6、最后,$ output即是去除重复后的二维数组。

来点实际代码理解一下:

$keyname_Arr= array_keys(end($resource_arr)); //存储内层数组的键名//使用'-'作为分隔将数组拼接成字符串foreach ($resource_arr as $v){ $v = join("-",$v); $temp[] = $v;}//去掉重复的字符串,也就是重复的一维数组$temp = array_unique($temp);//再将拆开的数组重新组装foreach ($temp as $k => $v){ $tempnew = explode("-",$v);//拆分去重之后的字符串 foreach($tempnew as $tempkey => $tempval) $output[$k][$keyname_Arr[$tempkey]] = $tempval;}

Cion.记载于2016/05/03夜.

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
PHP Dependency Injection Container: A Quick StartPHP Dependency Injection Container: A Quick StartMay 13, 2025 am 12:11 AM

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

Dependency Injection vs. Service Locator in PHPDependency Injection vs. Service Locator in PHPMay 13, 2025 am 12:10 AM

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.

PHP performance optimization strategies.PHP performance optimization strategies.May 13, 2025 am 12:06 AM

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

PHP Email Validation: Ensuring Emails Are Sent CorrectlyPHP Email Validation: Ensuring Emails Are Sent CorrectlyMay 13, 2025 am 12:06 AM

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

How to make PHP applications fasterHow to make PHP applications fasterMay 12, 2025 am 12:12 AM

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

PHP Performance Optimization Checklist: Improve Speed NowPHP Performance Optimization Checklist: Improve Speed NowMay 12, 2025 am 12:07 AM

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

PHP Dependency Injection: Improve Code TestabilityPHP Dependency Injection: Improve Code TestabilityMay 12, 2025 am 12:03 AM

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.

PHP Performance Optimization: Database Query OptimizationPHP Performance Optimization: Database Query OptimizationMay 12, 2025 am 12:02 AM

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

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

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

Hot Article

Hot Tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),