Avoid N 1 query problems, reduce the number of database queries by loading associated data in advance; 2. Select only the required fields to avoid loading complete entities to save memory and bandwidth; 3. Use cache strategies reasonably, such as Doctrine's secondary cache or Redis cache high-frequency query results; 4. Optimize the entity life cycle and call clear() regularly to free up memory to prevent memory overflow; 5. Ensure that the database index exists and analyze the generated SQL statements to avoid inefficient queries; 6. Disable automatic change tracking in scenarios where changes are not required, and use arrays or lightweight modes to improve performance. Correct use of ORM requires combining SQL monitoring, caching, batch processing and appropriate optimization to ensure application performance while maintaining development efficiency.

The settings.json file is located in the user-level or workspace-level path and is used to customize VSCode settings. 1. User-level path: Windows is C:\Users\\AppData\Roaming\Code\User\settings.json, macOS is /Users//Library/ApplicationSupport/Code/User/settings.json, Linux is /home//.config/Code/User/settings.json; 2. Workspace-level path: .vscode/settings in the project root directory

PHP's garbage collection mechanism is based on reference counting, but circular references need to be processed by a periodic circular garbage collector; 1. Reference count releases memory immediately when there is no reference to the variable; 2. Reference reference causes memory to be unable to be automatically released, and it depends on GC to detect and clean it; 3. GC is triggered when the "possible root" zval reaches the threshold or manually calls gc_collect_cycles(); 4. Long-term running PHP applications should monitor gc_status() and call gc_collect_cycles() in time to avoid memory leakage; 5. Best practices include avoiding circular references, using gc_disable() to optimize performance key areas, and dereference objects through the ORM's clear() method.

ReadonlypropertiesinPHP8.2canonlybeassignedonceintheconstructororatdeclarationandcannotbemodifiedafterward,enforcingimmutabilityatthelanguagelevel.2.Toachievedeepimmutability,wrapmutabletypeslikearraysinArrayObjectorusecustomimmutablecollectionssucha

First, use JavaScript to obtain the user system preferences and locally stored theme settings, and initialize the page theme; 1. The HTML structure contains a button to trigger topic switching; 2. CSS uses: root to define bright theme variables, .dark-mode class defines dark theme variables, and applies these variables through var(); 3. JavaScript detects prefers-color-scheme and reads localStorage to determine the initial theme; 4. Switch the dark-mode class on the html element when clicking the button, and saves the current state to localStorage; 5. All color changes are accompanied by 0.3 seconds transition animation to enhance the user

To create an HTML unordered list, you need to use a tag to define a list container. Each list item is wrapped with a tag, and the browser will automatically add bullets; 1. Create a list with a tag; 2. Each list item is defined with a tag; 3. The browser automatically generates default dot symbols; 4. Sublists can be implemented through nesting; 5. Use the list-style-type attribute of CSS to modify the symbol style, such as disc, circle, square, or none; use these tags correctly to generate a standard unordered list.

Use performance analysis tools to locate bottlenecks, use VisualVM or JProfiler in the development and testing stage, and give priority to Async-Profiler in the production environment; 2. Reduce object creation, reuse objects, use StringBuilder to replace string splicing, and select appropriate GC strategies; 3. Optimize collection usage, select and preset initial capacity according to the scene; 4. Optimize concurrency, use concurrent collections, reduce lock granularity, and set thread pool reasonably; 5. Tune JVM parameters, set reasonable heap size and low-latency garbage collector and enable GC logs; 6. Avoid reflection at the code level, replace wrapper classes with basic types, delay initialization, and use final and static; 7. Continuous performance testing and monitoring, combined with JMH

SemanticHTMLimprovesbothSEOandaccessibilitybyusingmeaningfultagsthatconveycontentstructure.1)ItenhancesSEOthroughbettercontenthierarchywithproperheadinglevels,improvedindexingviaelementslikeand,andsupportforrichsnippetsusingstructureddata.2)Itboostsa