Swift区间运算符和for-in循环

1.区间运算符

•闭区间[a,b]-------> a...b
•前闭后开区间[a,b)------->a..<b

2.for-in循环

for 变量名 in 区间
{ ... }

例子：

   for index in 1...10{
       println("\(index)")
       //index 是一个常量，不需要显示声明
   }

遍历一个数组

   var arrays = ["a","b","c","d","e"]
   for i in 0..<arrays.count
   {
       println(arrays[i])
   }

3.逻辑运算符

•与---------> a && b
•或---------> a || b
•非---------> !a