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- What are multiple exception catch blocks in PHP 7?
- MultiplecatchblocksinPHP7allowhandlingdifferentexceptionsseparately.Youcanwritespecificlogicforeachexceptiontype,suchasloggingdatabaseerrorsdifferentlyorreturningcustommessagesforinvalidinput.1.Eachcatchblockspecifiesanexceptiontypetohandle.2.Orderma
- PHP Tutorial . Backend Development 1013 2025-06-29 01:22:40
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- How do I format output in PHP using printf() or sprintf()?
- PHP's printf() and sprintf() functions provide fine control over variable display through format specifiers. printf() directly outputs the formatted string, while sprintf() returns the string for subsequent use. The format specifier includes optional parameter index, flag, width, precision and type, such as %d represents an integer and %.2f represents a floating point number that retains two decimal places. Common use cases include numerical formatting with padding and precision, text alignment, and reuse of parameters in different orders. Notes include ensuring that the format specifier matches the number of parameters, avoiding data truncation caused by type mixing, and prioritizing the use of special functions to handle localized values. Example: printf("d",7)
- PHP Tutorial . Backend Development 446 2025-06-29 00:53:20
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- What are Disjunctive Normal Form (DNF) Types in PHP 8.2?
- PHP8.2 supports the Dissociation Paradigm (DNF) type, allowing developers to use union and intersection types in type declarations. 1. The DNF type allows the combination of intersection (&) and union (|) with brackets, such as (A&B)|(C&D), which means that the parameters can be the intersection of A and B or the intersection of C and D; 2. This feature solves the problem that the previous version cannot directly express "union between multiple intersections"; 3. Practical applications include handling scenarios such as interface combination and conditional dependencies to improve the accuracy and security of API design; 4. When using it, you need to pay attention to the need to group in brackets, not nest complex expressions, and may affect readability.
- PHP Tutorial . Backend Development 415 2025-06-29 00:49:51
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- How to build a RESTful API with PHP?
- The key steps to build a RESTful API to use PHP are as follows: 1. Design a clear routing structure, which can be implemented by parsing URLs and HTTP methods or using frameworks (such as Slim, Lumen); 2. Use JSON as the data format and set the correct response status code (such as 200, 201, 400, 404, 500); 3. Strengthen data verification and security, use preprocessing statements to prevent SQL injection, and consider adding an identity authentication mechanism (such as JWT or APIKey) to ensure that the interface is safe and reliable.
- PHP Tutorial . Backend Development 678 2025-06-29 00:02:41
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- What are the different types of arrays in PHP (indexed, associative)?
- There are two main array types in PHP: index arrays and associative arrays. 1. The index array uses automatically allocated numeric keys, which are suitable for lists with important order, such as $fruits=array("Apple","Banana","Cherry"), access elements through indexes, such as $fruits[0] to get "Apple"; 2. Associating arrays uses custom string keys, such as $ages=array("John"=>25,"Jane"=>30), accesses through key names
- PHP Tutorial . Backend Development 642 2025-06-28 02:26:11
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- What is the difference between include and require in PHP?
- In PHP, the main difference between include and require is that the error is not found in the handling of the file: include generates a warning and continues executing the script, while require causes a fatal error and stops the script immediately. 1.include is suitable for non-critical files, such as sidebar or footer. If the file is missing, only a warning will be prompted and the script will continue to be executed; 2.require is used for critical files, such as configuration files or core libraries. If the file is missing, the script will be stopped immediately to avoid potential problems; 3.include_once and require_once ensure that the file is included only once to prevent repeated declarations; 4. When selecting, it should be determined based on the importance of the file. Use require for key files, optional parts
- PHP Tutorial . Backend Development 304 2025-06-28 02:25:51
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- How do I prevent cross-site request forgery (CSRF) attacks in PHP?
- TopreventCSRFattacksinPHP,implementanti-CSRFtokens.1)Generateandstoresecuretokensusingrandom_bytes()orbin2hex(random_bytes(32)),savethemin$_SESSION,andincludetheminformsashiddeninputs.2)ValidatetokensonsubmissionbystrictlycomparingthePOSTtokenwiththe
- PHP Tutorial . Backend Development 332 2025-06-28 02:25:31
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- How do I use transactions to ensure data consistency in PHP?
- When using database transactions in PHP, the key to ensuring data consistency is to perform multiple operations as a whole, either all succeed or all fail. The specific steps are as follows: 1. Use PDO or MySQLi to turn off automatic submission; 2. Execute SQL statements; 3. If all operations are successful, submit the transaction; 4. If an exception occurs, roll back the transaction. Additionally, you should always use the try-catch block to catch errors and make sure to use the InnoDB engine to support transaction processing.
- PHP Tutorial . Backend Development 628 2025-06-28 02:25:00
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- How to execute PHP scripts on a web server?
- Running PHP scripts requires the following steps: 1. Make sure that the server has PHP installed and enabled, and Linux can be installed and checked with commands; 2. Place the .php file in the root directory of the server document such as /var/www/html/ or C:\xampp\htdocs\; 3. Configure Apache or Nginx to handle PHP requests, enable the module or use PHP-FPM if necessary; 4. Set correct permissions and adjust the error prompts to ensure safety. After completing the above steps, restart the service and access the execution results through the browser.
- PHP Tutorial . Backend Development 225 2025-06-28 02:24:41
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- How do I use if statements to execute code based on conditions?
- If statement is used for programs to execute code according to conditions. Its core points include: 1. Use the if keyword to be followed by conditions and end with a colon; 2. Indent the code block to define the execution range; 3. Execute the corresponding code when the condition is True. In addition, you can use elif to perform additional condition checks, else to handle the remaining situations, and make multiple conditions judgments by combining and or, not. At the same time, you need to avoid common errors such as =-confusion with ==, missing colons and indentation.
- PHP Tutorial . Backend Development 768 2025-06-28 02:24:11
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- How do I use try, catch, and finally blocks to handle exceptions?
- Use try-catch-finally to effectively handle exceptions to ensure the stable operation of the program. 1. The trick block wraps the code that may be wrong; 2. The catch block catches and handles exceptions, and the specific exceptions should be caught first and then the general exceptions should be caught; 3. The finally block will be executed regardless of whether an exception occurs, which is suitable for resource cleaning. Avoid errors such as empty capture, excessively broad catch, large-scale try blocks, and using exceptions for regular processes. In addition, some serious errors such as OutOfMemoryError cannot be caught and processed. Mastering this structure can help improve program robustness.
- PHP Tutorial . Backend Development 361 2025-06-28 02:23:51
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- How to run PHP files with Docker?
- The key to running PHP files with Docker is to mount the directory and select the appropriate image. The specific steps are as follows: 1. Prepare the local PHP project directory structure such as myapp/storage index.php; 2. Use the official PHP image such as php:8.2-apache and mount the local directory to the container's /var/www/html through the -v parameter; 3. Use the dockerrun command to start the container and map the port such as 8080; 4. If you need CLI mode, use php:8.2-cli and specify the execution script; 5. Pay attention to file permissions, path matching and version compatibility; 6. You can write Dockerfile to build a custom image to simplify the deployment process.
- PHP Tutorial . Backend Development 527 2025-06-28 02:23:31
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- How do I use string functions in PHP (e.g., strlen(), strpos(), substr(), str_replace())?
- How to process text using string functions in PHP? 1. Use strlen() to get the string length, for example, strlen("Hello") returns 5, which is suitable for verifying the input length, but note that multi-byte characters need to use mb_strlen(). 2. Use strpos() to find the location of the substring, such as strpos("Thequickbrownfox","brown") to return 10, which is often used to check the mailbox or URL format. Note that using ===false to determine that it is not found, and you can use strpos() to perform case-insensitive searches. 3.Use substr()
- PHP Tutorial . Backend Development 702 2025-06-28 02:23:11
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- Tutorial on using Vagrant to build a PHP development environment
- ThisarticleexplainshowtosetupaPHPdevelopmentenvironmentusingVagrant.1.InstallVirtualBoxandVagrant,theninitializeaVagrantfilewithabaseboxlikebento/ubuntu-20.04.2.ConfiguretheVagrantfilewithprivateIP,syncedfolders,andforwardedports.3.StarttheVMwithvagr
- PHP Tutorial . Backend Development 720 2025-06-28 02:22:50
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