public static void SavePerson(Person p)
{
}
public static void Exam()
{
//未命名元组
var unnamed = ("one", "two");
//命名元组
var named = (first : "one", second : "two");
//用变量名初始化元组
var sum = 12.5;
var count = 5;
var accumulation = (sum, count);
Console.WriteLine(JsonConvert.SerializeObject(named));
Console.WriteLine(accumulation.ToString());
Console.WriteLine($"{accumulation.sum},{accumulation.Item1}");
//元组投影初始值设定项,可以投影字段名
var local1 = 5;
var local2 = "some text";
var tuple = (one : local1, two : local2);
var str = "the answer to everything";
var mixedTuple = (42, str);
Console.WriteLine($"{mixedTuple.Item1},{mixedTuple.str}");
Console.WriteLine(tuple.one);
Console.WriteLine(tuple.Item1);
var pt1 = (X : 3, Y : 4);
var pt2 = (X : 5, Y : 6);
//字段名有歧义时，不会投影语义名称
var mixedp = (pt1.X, pt2.X);
Console.WriteLine(mixedp.Item1);
//元组比较
var left = (a : 5, b : 10);
var right = (a : 5, b : 10);
Console.WriteLine(left == right);
(int a, int b)? nullableTuple = right;
Console.WriteLine(left == nullableTuple);
//会对每个成员执行隐式转换
(int?a, int?b)nullableTuple2 = right;
Console.WriteLine(left == right);
(long a, int b)longFirst = (5, 10);
Console.WriteLine(longFirst == right);
//成员名不参与比较
var pair = (z : 5, n : 6);
Console.WriteLine(pair == pt2);
//析构
var person = new Person("Li", "Ming");
var(first, last) = person;
Console.WriteLine($"析构：{first},{last}");
var(_, _, age) = person;
Console.WriteLine($"弃元：{person.Age}");
//元组作为out参数
Dictionary <int, (int, string)> dict = new Dictionary <int, (int, string)>();
dict.Add(1, (234, "first"));
dict.Add(2, (456, "second"));
dict.Add(3, (789, "third"));
dict.TryGetValue(2, out (int num, string place)pair2);
Console.WriteLine($"{pair2.num},{pair2.place}");
}