精选的 PHP 代码片段和学习资料可以让你在 30 秒内学会

 # 30 seconds of php code > A curated collection of useful PHP snippets that you can understand in 30 seconds or less. Note: This project is inspired by [30 Seconds of Code](https://github.com/Chalarangelo/30-seconds-of-code), but there is no affiliation with that project. ## Table of Contents ### 📚 Array <details> <summary>View contents</summary> * [`all`](#all) * [`any`](#any) * [`chunk`](#chunk) * [`deepFlatten`](#deepflatten) * [`drop`](#drop) * [`findLast`](#findlast) * [`findLastIndex`](#findlastindex) * [`flatten`](#flatten) * [`groupBy`](#groupby) * [`hasDuplicates`](#hasduplicates) * [`head`](#head) * [`last`](#last) * [`pluck`](#pluck) * [`pull`](#pull) * [`reject`](#reject) * [`remove`](#remove) * [`tail`](#tail) * [`take`](#take) * [`without`](#without) * [`orderBy`](#orderby) </details> ### ➗ Math <details> <summary>View contents</summary> * [`average`](#average) * [`factorial`](#factorial) * [`fibonacci`](#fibonacci) * [`gcd`](#gcd) * [`isEven`](#iseven) * [`isPrime`](#isprime) * [`lcm`](#lcm) * [`median`](#median) * [`maxN`](#maxn) * [`minN`](#minn) * [`approximatelyEqual`](#approximatelyequal) * [`clampNumber`](#clampnumber) </details> ### 📜 String <details> <summary>View contents</summary> * [`endsWith`](#endswith) * [`firstStringBetween`](#firststringbetween) * [`isAnagram`](#isanagram) * [`isLowerCase`](#islowercase) * [`isUpperCase`](#isuppercase) * [`palindrome`](#palindrome) * [`startsWith`](#startswith) * [`countVowels`](#countvowels) * [`decapitalize`](#decapitalize) </details> ### 🎛️ Function <details> <summary>View contents</summary> * [`compose`](#compose) * [`memoize`](#memoize) * [`curry`](#curry) * [`once`](#once) </details> --- ## 📚 Array ### all Returns `true` if the provided function returns `true` for all elements of an array, `false` otherwise. ```php function all($items, $func) { return count(array_filter($items, $func)) === count($items); } ``` <details> <summary>Examples</summary> ```php all([2, 3, 4, 5], function ($item) { return $item > 1; }); // true ``` </details> <br>[⬆ Back to top](#table-of-contents) ### any Returns `true` if the provided function returns `true` for at least one element of an array, `false` otherwise. ```php function any($items, $func) { return count(array_filter($items, $func)) > 0; } ``` <details> <summary>Examples</summary> ```php any([1, 2, 3, 4], function ($item) { return $item < 2; }); // true ``` </details> <br>[⬆ Back to top](#table-of-contents) ### chunk Chunks an array into smaller arrays of a specified size. ```php function chunk($items, $size) { return array_chunk($items, $size); } ``` <details> <summary>Examples</summary> ```php chunk([1, 2, 3, 4, 5], 2); // [[1, 2], [3, 4], [5]] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### deepFlatten Deep flattens an array. ```php function deepFlatten($items) { $result = []; foreach ($items as $item) { if (!is_array($item)) { $result[] = $item; } else { $result = array_merge($result, deepFlatten($item)); } } return $result; } ``` <details> <summary>Examples</summary> ```php deepFlatten([1, [2], [[3], 4], 5]); // [1, 2, 3, 4, 5] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### drop Returns a new array with `n` elements removed from the left. ```php function drop($items, $n = 1) { return array_slice($items, $n); } ``` <details> <summary>Examples</summary> ```php drop([1, 2, 3]); // [2,3] drop([1, 2, 3], 2); // [3] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### findLast Returns the last element for which the provided function returns a truthy value. ```php function findLast($items, $func) { $filteredItems = array_filter($items, $func); return array_pop($filteredItems); } ``` <details> <summary>Examples</summary> ```php findLast([1, 2, 3, 4], function ($n) { return ($n % 2) === 1; }); // 3 ``` </details> <br>[⬆ Back to top](#table-of-contents) ### findLastIndex Returns the index of the last element for which the provided function returns a truthy value. ```php function findLastIndex($items, $func) { $keys = array_keys(array_filter($items, $func)); return array_pop($keys); } ``` <details> <summary>Examples</summary> ```php findLastIndex([1, 2, 3, 4], function ($n) { return ($n % 2) === 1; }); // 2 ``` </details> <br>[⬆ Back to top](#table-of-contents) ### flatten Flattens an array up to the one level depth. ```php function flatten($items) { $result = []; foreach ($items as $item) { if (!is_array($item)) { $result[] = $item; } else { $result = array_merge($result, array_values($item)); } } return $result; } ``` <details> <summary>Examples</summary> ```php flatten([1, [2], 3, 4]); // [1, 2, 3, 4] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### groupBy Groups the elements of an array based on the given function. ```php function groupBy($items, $func) { $group = []; foreach ($items as $item) { if ((!is_string($func) && is_callable($func)) || function_exists($func)) { $key = call_user_func($func, $item); $group[$key][] = $item; } elseif (is_object($item)) { $group[$item->{$func}][] = $item; } elseif (isset($item[$func])) { $group[$item[$func]][] = $item; } } return $group; } ``` <details> <summary>Examples</summary> ```php groupBy(['one', 'two', 'three'], 'strlen') // [3 => ['one', 'two'], 5 => ['three']] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### hasDuplicates Checks a flat list for duplicate values. Returns `true` if duplicate values exists and `false` if values are all unique. ```php function hasDuplicates($items) { return count($items) > count(array_unique($items)); } ``` <details> <summary>Examples</summary> ```php hasDuplicates([1, 2, 3, 4, 5, 5]); // true ``` </details> <br>[⬆ Back to top](#table-of-contents) ### head Returns the head of a list. ```php function head($items) { return reset($items); } ``` <details> <summary>Examples</summary> ```php head([1, 2, 3]); // 1 ``` </details> <br>[⬆ Back to top](#table-of-contents) ### last Returns the last element in an array. ```php function last($items) { return end($items); } ``` <details> <summary>Examples</summary> ```php last([1, 2, 3]); // 3 ``` </details> <br>[⬆ Back to top](#table-of-contents) ### pluck Retrieves all of the values for a given key: ```php function pluck($items, $key) { return array_map( function($item) use ($key) { return is_object($item) ? $item->$key : $item[$key]; }, $items); } ``` <details> <summary>Examples</summary> ```php pluck([ ['product_id' => 'prod-100', 'name' => 'Desk'], ['product_id' => 'prod-200', 'name' => 'Chair'], ], 'name'); // ['Desk', 'Chair'] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### pull Mutates the original array to filter out the values specified. ```php function pull(&$items, ...$params) { $items = array_values(array_diff($items, $params)); return $items; } ``` <details> <summary>Examples</summary> ```php $items = ['a', 'b', 'c', 'a', 'b', 'c']; pull($items, 'a', 'c'); // $items will be ['b', 'b'] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### reject Filters the collection using the given callback. ```php function reject($items, $func) { return array_values(array_diff($items, array_filter($items, $func))); } ``` <details> <summary>Examples</summary> ```php reject(['Apple', 'Pear', 'Kiwi', 'Banana'], function ($item) { return strlen($item) > 4; }); // ['Pear', 'Kiwi'] ``` </details> <br>[⬆ Back to top](#table-of-contents) ### remove Removes elements from an array for which the given function returns false. ```php function remove($items, $func) { $filtered = arra