## Swift 運算符之范圍運算符for-in ### 區間運算符 | 運算符 |舉例 | 作用 | | --- | --- | --- | | `a...b` | 相當于數學里的`[a,b]` | 閉合區間 | | `a..<b` | 相當于數學里的`[a,b)` | 前閉后開區間 | ### 閉合區間 ``` for index in 1...10 { index } ``` ### 前閉后開區間 ``` for index in 0 ..< 10 { index } // let arr = [1,2,3,4,5,6,7,10] for i in 0..<arr.count { print(arr[i]) } ``` ### 對數組遍歷 ``` var array: Array<String> = ["A","V","X","S"] for arr in array{ arr } // 遍歷數組的鍵值 for (key,value) in array.enumerated(){ key value } ``` ### 遍歷字典 ``` var dict: Dictionary<Int,String> = [1:"A",2:"B",3:"d"] // 遍歷字典的key for key in dict.keys{ key } // 遍歷字典的value for value in dict.values{ value } ``` ### 遍歷集合 ``` var set: Set<String> = ["A","V","X","S"] for value in set{ value } ```