问题描述

Swift 2.0泛型例子解答

func anyCommonElements (lhs: T, _ rhs: U) -> Bool {
for lhsItem in lhs {
for rhsItem in rhs {
if lhsItem == rhsItem {
return true
}
}
}
return false
}
anyCommonElements([1, 2, 3], [3])

练习： 修改anyCommonElements(_:_:)函数来创建一个函数，返回一个数组，内容是两个序列的共有元素。

解决方案

 func anyCommonElements  (lhs: T, rhs: U) -> Bool {
    for lhsItem in lhs {
        for rhsItem in rhs {
            if lhsItem == rhsItem {
                return true
            }
        }
    } 

    return false
} 

anyCommonElements([1, 2, 3], [3]) 

func whichCommonElements  (lhs: T, rhs: U) -> Array {
    var toReturn = Array() 

    for lhsItem in lhs {
        for rhsItem in rhs {
            if lhsItem == rhsItem {
                toReturn.append(lhsItem)
            }
        }
    } 

    return toReturn
} 

whichCommonElements([1, 2, 3], [3, 2])