## 組 > 將包含基本類型的PHP數組包裝到數學集的類。 ### 創建 要創建Set，請僅使用包含基元的平面數組： ``` use \Phpml\Math\Set; $set = new Set([1, 2, 2, 3, 1.1, -1, -10]); $set->toArray(); // return [-10, -1, 1, 1.1, 2, 3] $set = new Set(['B', '', 'A']); $set->toArray(); // return ['', 'A', 'B'] ``` 注入的數組按`SORT_ASC`排序，刪除重復項并重寫索引 ***** ### 并集 創建兩個集合的并集： ``` use \Phpml\Math\Set; $union = Set::union(new Set([1, 3]), new Set([1, 2])); $union->toArray(); //return [1, 2, 3] ``` ***** ### 交集 創建兩個集合的交集： ``` use \Phpml\Math\Set; $intersection = Set::intersection(new Set(['A', 'C']), new Set(['B', 'C'])); $intersection->toArray(); //return ['C'] ``` ***** ### 補充 創建兩個集的集合論差異： ``` use \Phpml\Math\Set; $difference = Set::difference(new Set(['A', 'B', 'C']), new Set(['A'])); $union->toArray(); //return ['B', 'C'] ``` ***** ### 添加元素 ``` use \Phpml\Math\Set; $set = new Set([1, 2]); $set->addAll([3]); $set->add(4); $set->toArray(); //return [1, 2, 3, 4] ``` ***** ### 刪除元素 ``` use \Phpml\Math\Set; $set = new Set([1, 2]); $set->removeAll([2]); $set->remove(1); $set->toArray(); //return [] ``` ***** ### 檢查成員 ``` use \Phpml\Math\Set; $set = new Set([1, 2]); $set->containsAll([2, 3]); //return false $set->contains(1); //return true ``` ***** ### 基數 ``` use \Phpml\Math\Set; $set = new Set([1, 2]); $set->cardinality(); //return 2 ``` ***** ### 是否為空 ``` use \Phpml\Math\Set; $set = new Set(); $set->isEmpty(); //return true ``` ***** ### 使用循環 ``` use \Phpml\Math\Set; $set = new Set(['A', 'B', 'C']); foreach($set as $element) { echo "$element, "; } // echoes A, B, C ```