## Swift 运算符之范围运算符for-in ### 区间运算符 | 运算符 |举例 | 作用 | | --- | --- | --- | | `a...b` | 相当于数学里的`[a,b]` | 闭合区间 | | `a..<b` | 相当于数学里的`[a,b)` | 前闭后开区间 | ### 闭合区间 ``` for index in 1...10 { index } ``` ### 前闭后开区间 ``` 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]) } ``` ### 对数组遍历 ``` var array: Array<String> = ["A","V","X","S"] for arr in array{ arr } // 遍历数组的键值 for (key,value) in array.enumerated(){ key value } ``` ### 遍历字典 ``` var dict: Dictionary<Int,String> = [1:"A",2:"B",3:"d"] // 遍历字典的key for key in dict.keys{ key } // 遍历字典的value for value in dict.values{ value } ``` ### 遍历集合 ``` var set: Set<String> = ["A","V","X","S"] for value in set{ value } ```