swift.reversed()有相同的效果

代码演示

var dataSource : [Int] = [0,1,2,3,4,5,6,7,8,9]
func exchange(dataSource : [Int]) -> [Int]{
    var data = dataSource
    let count = dataSource.count
    for i in 0 ..< count / 2{
        let t = data[i]
        data[i] = data[count - i - 1]
        data[count - i - 1] = t
    }
    return data
}