Code examples for PHP Infinitus classification (recursive and tree)

PHParrayscansimulatestackandqueuebehaviorsusingspecificfunctions,withkeydifferencesinlogicandperformance.Forastack(LIFO),1.usearray_push()toaddelementstotheend,2.usearray_pop()toremovefromtheend—fastandefficient.Foraqueue(FIFO),1.usearray_push()toadd

This article explains in detail how to rewrite dynamic URLs (such as domain/some.php?f=query-string) into more aesthetically pleasing static forms (such as domain/query-string) using the .htaccess and mod_rewrite modules. The focus is on analyzing common "slash" errors in the RewriteRule pattern and providing the correct configuration method to help developers effectively implement URL optimization.

After deleting elements with unset(), the PHP index array will have key gaps, resulting in keys no longer continuous; 2. The key gap will affect loops, JSON encoding and functions that rely on continuous indexes; 3. The array can be re-indexed through array_values() to generate continuous keys starting from 0; 4. The array_filter() will retain the original key, and the array_values() needs to be called manually to re-index; 5. Use array_splice() to delete elements to automatically re-index; 6. Before JSON encoding, you should ensure that the keys are continuous, otherwise objects may be output instead of arrays; 7. When the keys of the associative array are meaningful, re-index should be avoided to avoid losing key names; 8. Only when the array needs to be used as an ordered list

PHP8.1enhancesarraymergingwiththespreadoperator(...),whichunpacksiterablesintoarrayliterals,offeringcleanersyntaxthanarray_merge().1.Itworksinarraydeclarations,mergingindexedarraysintuitively:[...$a,...$b]preservesorder.2.Forassociativearrays,laterva

Literalinitializationisbestforsmall,staticdatasetsusingsyntaxlikeconstarr=[1,2,3].2.ConstructoranddynamicmethodslikenewArray(n)orArray(n).fill()areidealforpredefinedsizesorrepeatedvalues,withcautionagainstsparsearraysinJavaScript.3.Convertingexisting

PHP arrays can implement stacks and queues through built-in functions. 1. The stack uses array_push() and array_pop(), and the time complexity is O(1), which is suitable for efficient operations; 2. The queue uses array_push() and array_shift(), but array_shift() is O(n), and the performance decreases with the amount of data; 3. The production environment should give priority to using SplStack and SplQueue, which is based on a bidirectional linked list, and the operations are O(1), which has better performance; 4. Native arrays are suitable for small-scale data or prototype development, and should be avoided in queues during large-scale high-frequency operations.

?In PHP, the type can be empty, which can improve the type safety and readability of the code; 1. When used for optional parameters, make sure that the incoming value is the specified type or null; 2. For return values that may not be found, clearly inform the caller that it may return null; 3. For scenarios where optional data exists such as APIs, accurately model the data structure; when used, it should only be used when null makes sense, avoid repeated definitions with the default null, combine the null and handle null values with the ?? and ?-> operators, and note that it cannot be used for void types. After PHP8, string is equivalent to string|null, but the former is more concise, and reasonable use can significantly reduce runtime errors.

Thedo-whileloopinPHPisidealforpost-testlogicbecauseitguaranteesatleastoneexecutionoftheloopbodybeforeevaluatingthecondition.1.Useitwhenanactionmustrunatleastoncebeforecheckingrepetition,suchasuserinputvalidation,wherethepromptmustappearbeforevalidati