定義

元組是由若幹個類型的數據組成，組成元組的數據叫做元素，每個元素的類型都可以是任意的。

用法一

let tuples1 = ("Hello", "World", 2017)

//元組跟數組一樣，其元素的角標是從0開始 可以用 tuple1.0 tuple1.1 tuple1.2進行取值

print("get first value \(tuples1.0), get the second value \(tuples1.1), get the third value \(tuples1.2)")

用法二

let tuples2 = (first:"Hello", second:"World", third:2017)

//此中用法的元組的取值可以用 tuple2.first tuple2.second tuple3.third

print("get the first value \(tuples2.first), get the second value \(tuples2.second), get the third value \(tuples2.third)")

用法三

//變量接收數值法

let (x, y, z) = ("Hello", "World", 2017);

print("get x is \(x) get y is \(y) get z is \(z)")

//用_取出某些元素的值忽略_對應的值

let (a, _, b) = ("Hello", "World", 2017);

print("get x is \(a) get z is \(b)")

元組值得修改

let tuples2 = (first:"Hello", second:"World", third:2017)

//此中用法的元組的取值可以用 tuple2.first tuple2.second tuple3.third

print("get the first value \(tuples2.first), get the second value \(tuples2.second), get the third value \(tuples2.third)")

//此時會報錯

//tuples2.first = "test"; 應將tuple2前的let 改成var可將元組變成可變元組

var tuples2 = (first:"Hello", second:"World", third:2017)

//此中用法的元組的取值可以用 tuple2.first tuple2.second tuple3.third

var print("get the first value \(tuples2.first), get the second value \(tuples2.second), get the third value \(tuples2.third)")

tuples2.first = "test";

print("get the first value \(tuples2.first), get the second value \(tuples2.second), get the third value \(tuples2.third)")

元組的高級應用

定義一個可以交換一個數組中兩個元素的函數

func swap<T>(_ nums: inout [T], _ p: Int, _ q: Int) {

(nums[p], nums[q]) = (nums[q], nums[p])

}

var array = ["Hello", "World", 2017] as [Any]

for value in array {

print(value);

}

swap(&array, 0, 2)

for value in array {

print(value);

}

Swift學習之元組（Tuple）