Swift - for-in 循环

for-in 循环迭代遍历项目集合，例如数字范围、数组中的项目或字符串中的字符。

语法

Swift 4 编程语言中for-in 循环的语法如下：

for index in var {
   statement(s)
}

示例

var someInts:[Int] = [10, 20, 30]

for index in someInts {
   print( "Value of index is \(index)")
}

执行上述代码后，将产生以下结果：

Value of index is 10
Value of index is 20
Value of index is 30