current location：Home > Technical Articles > Daily Programming > PHP Knowledge
- Direction：
- All web3.0 Backend Development Web Front-end Database Operation and Maintenance Development Tools PHP Framework Daily Programming WeChat Applet Common Problem Other Tech CMS Tutorial Java System Tutorial Computer Tutorials Hardware Tutorial Mobile Tutorial Software Tutorial Mobile Game Tutorial
- Classify：
- PHP tutorial MySQL Tutorial HTML Tutorial CSS Tutorial
-
- How do I store data in a session using the $_SESSION superglobal?
- Tostoredatainasessionusing$_SESSIONinPHP,firstcallsession_start()beforeanyoutput.Thenassignvaluestokeysinthe$_SESSIONarray.1.Startthesessionwithsession_start()atthescript'sbeginning.2.Storedatausingkey-valuepairslike$_SESSION['key']=value.3.Accessorm
- PHP Tutorial . Backend Development 905 2025-06-25 01:07:10
-
- What are classes in PHP, and how do I create them?
- InPHP,classesaredefinedusingtheclasskeywordandserveastemplatesforcreatingobjectswithspecificpropertiesandmethods.Todefineabasicclass,youdeclarepropertiesandmethodsinsidetheclassbody,suchasclassCar{public$color;public$model;publicfunctionstartEngine()
- PHP Tutorial . Backend Development 587 2025-06-25 01:06:30
-
- How do I retrieve data from a database using mysqli_query() or PDO::query()?
- mysqli_query() and PDO::query() are both used to query databases in PHP, but their characteristics are different. 1.mysqli_query() only supports MySQL, and needs to manually check connection and execution errors, use fetch_assoc() to read the results, and finally close the connection; 2. PDO::query() supports a variety of databases, and can automatically catch errors through setAttribute setting exception mode, and use fetch() combined with PDO::FETCH_ASSOC to read data without manually closing the connection. Suggestion: If you only use MySQL and pursue simplicity, choose mysqli_query(); if you need portability or complex project, choose P
- PHP Tutorial . Backend Development 502 2025-06-25 01:06:10
-
- How do I use comments in PHP code? (//, /* */, #)
- There are three commonly used annotation methods in PHP: //, // and #, which are suitable for different scenarios. 1. Use // for single-line comments, suitable for quick explanations or disabling one-line code, which can be placed above or on the right side of the code line; 2. Use // for multi-line comments, suitable for long paragraph descriptions or temporary disabling multi-line code, but be careful not to be nested; 3. Use # for single-line comments in Shell style, which are rare and are mainly used in old projects or mixed scripts. It is recommended to explain the code logic rather than the function to avoid redundancy while keeping comments and code updated synchronously.
- PHP Tutorial . Backend Development 182 2025-06-25 01:05:31
-
- What is the performance improvements in PHP 7 compared to PHP 5?
- PHP7 significantly improves performance, mainly due to the new ZendEngine 3.0. 1. The execution speed is faster, and the code execution efficiency is usually more than twice that of PHP5; 2. The memory consumption is lower and the memory usage is reduced by more than 50%; 3. Support modern web development requirements, such as type declaration, exception handling and OPcache optimization, making applications more stable and efficient. Therefore, upgrading to PHP7 can bring higher performance and better maintenance.
- PHP Tutorial . Backend Development 195 2025-06-25 01:02:11
-
- How to set PHP time zone?
- TosettherighttimezoneinPHP,usedate_default_timezone_set()functionatthestartofyourscriptwithavalididentifiersuchas'America/New_York'.1.Usedate_default_timezone_set()beforeanydate/timefunctions.2.Alternatively,configurethephp.inifilebysettingdate.timez
- PHP Tutorial . Backend Development 375 2025-06-25 01:00:30
-
- What is the switch statement in PHP, and how does it work?
- AswitchstatementinPHPisusedtoexecutedifferentcodeblocksbasedonthevalueofasinglevariableorexpression.1.Itevaluatesanexpressiononceandcomparesitagainstmultiplecasevalues.2.Eachmatchingcaserunsitscorrespondingcode,andthebreakstatementpreventsfall-throug
- PHP Tutorial . Backend Development 421 2025-06-25 01:00:11
-
- How do I iterate over an array in PHP using foreach?
- The method of using foreach to loop arrays in PHP has the following key points: 1. The basic syntax is foreach($arrayas$value), which is suitable for cases where only values ??need to be processed; 2. If you need to process keys and values ??at the same time, use foreach($arrayas$key=>$value); 3. For index arrays such as $fruits, you can get the values ??one by one through foreach($fruitsas$fruit); 4. In associative arrays such as $user, use the $field=>$value structure to get the keys and values ??at the same time; 5. If you want to modify the original array element, you need to pass it through reference, that is, use &$num, and loop
- PHP Tutorial . Backend Development 316 2025-06-25 00:59:32
-
- How to quickly test PHP code snippets?
- ToquicklytestaPHPcodesnippet,useanonlinePHPsandboxlike3v4l.orgorPHPize.onlineforinstantexecutionwithoutsetup;runcodelocallywithPHPCLIbycreatinga.phpfileandexecutingitviatheterminal;optionallyusephp-rforone-liners;setupalocaldevelopmentenvironmentwith
- PHP Tutorial . Backend Development 889 2025-06-25 00:58:21
-
- What are PHP frameworks (e.g., Laravel, Symfony, CodeIgniter)?
- PHP framework helps developers to efficiently build web applications by providing structured code. Common frameworks such as Laravel are used to quickly develop modern web applications with built-in authentication and API tools; Symfony is known for its stability and flexibility, suitable for large enterprise-level projects and is widely integrated into other systems; CodeIgniter is lightweight and fast, suitable for small websites or APIs without complex functions. Selecting a framework can improve maintenance and scalability, especially suitable for scenarios such as user authentication, complex database relationships, or REST routing, while simple projects can use native PHP to avoid redundancy.
- PHP Tutorial . Backend Development 437 2025-06-25 00:58:00
-
- How do I create and use image manipulation functions in PHP?
- TocreateanduseimagemanipulationfunctionsinPHP,usetheGDlibraryorImageMagick.1.InstallandenableGDorImageMagickdependingonyourneeds.2.UseGDforbasicoperationslikeresizing,watermarkingwithtextorimages,anddestroyingresourcesafteruse.3.UseImageMagickforadva
- PHP Tutorial . Backend Development 808 2025-06-25 00:56:01
-
- How do I move uploaded files to a permanent location on the server using move_uploaded_file()?
- TomoveanuploadedfileinPHP,usemove_uploaded_file()aftervalidatingtheuploadandsettingthecorrecttargetpath.First,checkiftheuploadwassuccessfulusing$_FILES['fileToUpload']['error']toensurenoerrorsoccurred.Next,defineasecuretargetpathbycombiningavaliddire
- PHP Tutorial . Backend Development 858 2025-06-25 00:55:41
-
- How to install Composer to manage PHP dependencies?
- It is not difficult to install Composer to manage PHP dependencies. 1. Download and install Composer. Windows users can download the installer. Linux/macOS users can generate composer.phar file through command download and move it to the global path; 2. Configure the global environment, such as using domestic mirrors to improve download speed and set automatic loading; 3. Create composer.json file in the project and use commands to add and update dependencies to ensure that the entry file contains the automatically generated autoload.php. The entire process requires attention to preconditions such as permissions, PHP version and PHPCLI environment.
- PHP Tutorial . Backend Development 836 2025-06-25 00:55:21
-
- How do I use htmlspecialchars() to escape HTML entities in user input?
- TosafelydisplayuserinputinHTMLusingPHP,usethehtmlspecialchars()function.1.Alwayspasstheinputthroughhtmlspecialchars($input,ENT_QUOTES,'UTF-8')toconvertspecialcharacterstoHTMLentities.2.Applyitwhenrenderinguser-generatedcontentlikeformsubmissions,comm
- PHP Tutorial . Backend Development 324 2025-06-25 00:55:01
Recommended Articles
Tool Recommendations
jQuery enterprise message form contact code
jQuery enterprise message form contact code is a simple and practical enterprise message form and contact us introduction page code.
form button
2024-02-29
HTML5 MP3 music box playback effects
HTML5 MP3 music box playback special effect is an mp3 music player based on HTML5 css3 to create cute music box emoticons and click the switch button.
Player special effects
2024-02-29
HTML5 cool particle animation navigation menu special effects
HTML5 cool particle animation navigation menu special effect is a special effect that changes color when the navigation menu is hovered by the mouse.
Menu navigation
2024-02-29
jQuery visual form drag and drop editing code
jQuery visual form drag and drop editing code is a visual form based on jQuery and bootstrap framework.
form button
2024-02-29
Organic fruit and vegetable supplier web template Bootstrap5
An organic fruit and vegetable supplier web template-Bootstrap5
Bootstrap template
2023-02-03
Bootstrap3 multifunctional data information background management responsive web page template-Novus
Bootstrap3 multifunctional data information background management responsive web page template-Novus
backend template
2023-02-02
Real estate resource service platform web page template Bootstrap5
Real estate resource service platform web page template Bootstrap5
Bootstrap template
2023-02-02
Simple resume information web template Bootstrap4
Simple resume information web template Bootstrap4
Bootstrap template
2023-02-02
Cute summer elements vector material (EPS PNG)
This is a cute summer element vector material, including the sun, sun hat, coconut tree, bikini, airplane, watermelon, ice cream, ice cream, cold drink, swimming ring, flip-flops, pineapple, conch, shell, starfish, crab, Lemons, sunscreen, sunglasses, etc., the materials are provided in EPS and PNG formats, including JPG previews.
PNG material
2024-05-09
Four red 2023 graduation badges vector material (AI EPS PNG)
This is a red 2023 graduation badge vector material, four in total, available in AI, EPS and PNG formats, including JPG preview.
PNG material
2024-02-29
Singing bird and cart filled with flowers design spring banner vector material (AI EPS)
This is a spring banner vector material designed with singing birds and a cart full of flowers. It is available in AI and EPS formats, including JPG preview.
banner picture
2024-02-29
Golden graduation cap vector material (EPS PNG)
This is a golden graduation cap vector material, available in EPS and PNG formats, including JPG preview.
PNG material
2024-02-27
Home Decor Cleaning and Repair Service Company Website Template
Home Decoration Cleaning and Maintenance Service Company Website Template is a website template download suitable for promotional websites that provide home decoration, cleaning, maintenance and other service organizations. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-05-09
Fresh color personal resume guide page template
Fresh color matching personal job application resume guide page template is a personal job search resume work display guide page web template download suitable for fresh color matching style. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-29
Designer Creative Job Resume Web Template
Designer Creative Job Resume Web Template is a downloadable web template for personal job resume display suitable for various designer positions. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28
Modern engineering construction company website template
The modern engineering and construction company website template is a downloadable website template suitable for promotion of the engineering and construction service industry. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28
